

- Full metal build - Mostly steel
- Integrated muzzle flash tracer unit
- Gate X-ASR MOSFET pre-installed
If you're interested in WWII replicas but need something stealthy, the Specna Arms STEN Mk II(S) RETRO AEG is ideal. A full metal build made almost entirely from steel, this STEN gun replica is inspired by the real steel Mk II(S) version, the integrally suppressed STEN gun used by the SOE (Special Operations Executive), the S denoting "special purpose".
Inside, we're treated to a muzzle flash tracer unit concealed inside the integral suppressor, a great addition for a more immersive firing experience. Also inside is a Gate X-ASR MOSFET, unique to the Specna Arms version. The X-ASR provides battery protection, a boost in trigger response thanks to improved electrical efficiency and diagnostics via its LED indicators.
The build is based around a version 7 gearbox, and now includes a grub screw-adjustable HOP-up unit to enhance long-range performance. If you're after an old-school primary with a clandestine edge, the Specna Arms STEN Mk II(S) RETRO AEG has your name on it!
Fast Delivery
Delivery & Postage
Here at Patrol Base, we send all our packages from our Warehouse based in the UK with the exception of European Warehouse Items. All of our parcels are sent with specially picked couriers to ensure your parcels get to you on time and in one piece.
For more information please check out our Delivery Information Page.
Estimates
Below are some rough postage prices for orders. Please note these are subject to change and are only a rough guide. For a more accurate postage estimate please use the Postage Calculator at the basket.
UK 3-5 day Standard
£6.95
From
1-2 Working Day Dispatch UK mainland
£9.95
From
Highlands / Islands
£24.99*
From
* Please note that Scottish Highlands, and Islands postage prices can vary wildly. Please refer to the Postage Calculator at the basket for the lowest possible price.
Returns
We want you to be absolutely happy with our products and services, so we provide the simple Patrol Base guarantee: if on receiving your item you are unhappy with your item for any reason then simply send it back to us. We will replace or refund the item.
You can return any item for any reason whatsoever, even if you have just changed your mind, within 14 days of receipt of the order. This is in addition to your rights under the Consumer Protection (Distance Selling) Regulations 2000.
For more information on returning products, and how to do it please visit our Returns Policy Page.
Description
Starting at the front, we can find the lengthy integral suppressor, made from aluminium with a removable front aperture. Unscrewing the aperture allows you to remove the integral tracer module and housing, after which you can unscrew the rear cap to extract the module itself and access the controls.
The mode selection button is on the front of the tracer module, offering muzzle flash/tracer and tracer-only modes to choose from. The USB Type-C charging port is also on the front of the module, but the cable to charge the tracer is not included. Throwing this extra bit of fun into the build at no extra cost genuinely impressed us, as it makes shooting the STEN Mk II(S) that bit more exciting!
To do appropriate justice to the real steel STEN Mk II(S), a mock canvas suppressor cover made from fabric is included and pre-installed, ensuring you get the "as issued" look straight out of the box. The suppressor itself can be unscrewed at the rear collar, providing access to the battery compartment of this front-wired build.
With the suppressor unscrewed, you'll find a Deans battery connector inside, to which you connect your choice of battery. We recommend a 7.4V 1450mAh LiPo in crane/nunchuck configuration for ease of fitment. There is plenty of space inside the suppressor for bigger batteries, though you'll have to stick with relatively long, slim designs.
Following the suppressor, we arrive at the receiver, made from sheet steel, just like the real STEN gun. As you'll receive it, the STEN will be in "storage" configuration, with the magazine well rotated to face downwards. To ready the STEN to shoot, you'll need to pull the catch on the front of the magazine well out, then rotate the magazine well by 90 degrees so it is positioned on the left side. This feature was included on most variants of the real STEN to allow it to be stored flat for transportation and parachute drops, though the further simplified Mk III had its magazine well welded in place.
With the magazine well in the storage position, you can access the adjustable HOP-up of the STEN through the small hole in the ejection port, using a small Allen key (size to be confirmed). This is a new addition to the very latest AGM STEN AEGs, replacing the older model's fixed HOP-up unit. The HOP-up allows you to tune the amount of backspin applied to your BBs and tune for different ammo weights, seeking the flattest possible trajectory.
The magazine release is on the top of the magazine well, allowing you to release the magazine by pushing downwards on the button. Compatibility-wise, the STEN Mk II(S) is good to go with AGM STEN/MP40/MP41 or Specna Arms MP40/STEN magazines and comes packaged with a 120-round mid-cap magazine. It's worth noting that the magazine cannot be inserted with the magazine well in the storage position.
Aft of the magazine well, the receiver is a simple layout, just like the real super-simple STEN. The mock charging handle is on the right side, complete with a track cut into the receiver with the "safety" notch appropriately represented. The safety notch was included to provide some level of safe carry for the STEN, which was legendarily prone to accidental discharges, especially if dropped.
The charging handle cannot be racked, but can be repositioned by unscrewing the handle itself. If you do choose to reposition the handle, please ensure you don't force the handle if it feels like it won't move; this could trap any internal wiring and cause faults.
Below the charging handle track, we can find a simple sling point, a welded steel bar, ideally suited to whatever sling setup you fancy. Being made from steel ensures this sling point is strong enough to go the distance and does appropriate justice to the real STEN gun.
Below the sling bar, we can find the trigger itself, protected by a stamped steel trigger guard. This flat-faced trigger is also a great match for the real STEN, ensuring visuals are on point across the entire build. There is no safety catch or fire selector switch on the STEN, so make sure you keep your finger away from the trigger unless you intend to shoot!
On top of the tube receiver, we can find our iron sights, made from stamped steel and welded into place. The front sight is a wide barley-corn style blade, paired with an aperture rear sight. Easy to align and generally well-liked by soldiers in the STEN era, these sights are fixed in place, ready for spray-and-pray fire supremacy!
At the rear, we come to the skeleton stock, made from stamped steel and a perfect match for the real Mk II(S) stock. Unlike the original Mk II stock, this stock is surprisingly comfortable for a STEN gun, though it is no match for early-war and late-war wood-stocked versions.
Inside, the STEN Mk II(S) is based around a version 7 gearbox, the same gearbox shape used in M14 AEG platforms. The shell is made from alloy and equipped with 18:1 ratio steel gears running on polycarbonate bushings. The newly added adjustable HOP-up unit should help provide the range needed to compete at outdoor events, and the Deans battery connector enhances electrical efficiency considerably compared to the mini-Tamiya connector on the previous version.
Unique to the Specna Arms Mk II(S) is the Gate X-ASR MOSFET, a smart-fuse type device which enhances electrical efficiency, protects your battery and provides limited diagnostics through its LED indicators. Though most of the effort has been put into the externals of this beast, the gearbox sounds remarkably smooth when shot, and the rate of fire is respectable, ideal for WW2 scenarios where shredding the enemy team with 30 rounds per second just isn't cricket!
Features
- Full metal build - All steel other than the Aluminium suppressor
- Integral suppressor with muzzle flash tracer module - Light 'em up!
- Mock canvas suppressor cover included - Completes the Mk II(S) look
- Rotatable magazine well - Rotate the magazine well to store the STEN flat, just like the real deal
- Grub screw-adjustable HOP-up - New design, access in "Storage" config through the port on the bolt
- Full automatic only - No semi, no safety!
- Receiver sling point - On the right side, steel build for strength & realism
- Skeleton semi-pistol-grip stock - A perfect match for the real Mk II(S)
- Front wired: Deans connector - Recommended battery: 7.4V 1450mAh LiPo
- Version 7 gearbox:
- Alloy shell
- Polycarbonate bushings
- Compatible with AGM STEN/MP40/MP41 AEG Magazines:
- 50rnd Low-cap magazine
- 120rnd Mid-cap magazine
- 300rnd High-cap magazine
Package Includes
- Specna Arms STEN Mk II(S) RETRO AEG
- 120rnd Mid-cap magazine
Special Instructions
Please note: The included muzzle flash tracer unit requires a USB Type-C cable to charge its internal battery. We recommend recharging the battery every 2-3 months to maintain battery health, regardless of usage.
Specification
Battery Included | No |
|---|
General
Platform Type | Submachine Gun |
|---|---|
Over 18 | Yes |
Defence / UKARA Required | Yes, No, |
Prebuilt | Yes |
Included Items | Magazine |
Skill Level | Regular Player |
Warnings | Li-Po Li-Po - Never Leave Charging Unattended Li-Po - Only Use Approved Chargers Li-Po - Charge in a Fire Safe Area |
Testing
Testing Notes | Tested using 0.20g Delta Armory EAGLE BBs |
|---|
Weight and Dimension
Weight (KG) | Approx.2.6KG |
|---|---|
Length | 97cm |
Construction
Primary Colour | Gun Metal Grey |
|---|---|
Construction | Steel receiver, magazine well assembly & stock. Aluminium suppressor. Fabric suppressor cover. |
Weapon Specific
Powered By | Electric |
|---|---|
Platform | STEN Mk II (S) |
Magazine Compatibility | AGM STEN/MP40 AEG Magazines |
Fire modes | Safe Full Automatic |
Safety Features | Trigger Lock |
Shooter Configuration | Right Handed |
Platform Scale | 1:1 |
Suggested BB Weight | 0.25g |
Hop-Up
HOP-Up Adjuster Type | Grub Key |
|---|---|
HOP-Up Adjustment Location | Accessible with the magazine well in "Storage" configuration, through the port on the top of the mock bolt. |
Furniture
Furniture |
|
|---|---|
Stock Type | Fixed |
Sight Type | Aperture Iron Sight |
Sling Options | Loop, Receiver, |
Barrel
Inner Barrel Diameter | 6.08mm |
|---|---|
Inner Barrel Length | 300mm |
Magazine Specific
Magazine Type | AEG, Medium Capacity, |
|---|---|
Magazine BB Capacity | Approx.120Rounds |
Electric Gun Specific Information
Gearbox
Gearbox Version | V7Gearbox |
|---|---|
Gearbox Wiring | Front Wired |
Battery Specific
Battery Voltage | 7.4V |
|---|---|
Battery Type | Li-Po |
Battery Connector | Deans |
Suggested Battery Configuration | Crane configuration |
Size guide
Joule Charts
Special Instructions
These table can be used as a reference to see if the BB weight you are using will be over acceptable Joulage limits at some Airsoft Sites in the UK. To check if the weight can be used chrono your weapon using the BB you intend to use, and then compare it to the chart.
FPS, Power and Joule Limits can vary from site to site, so please get in touch with where you're going to play with in advance to avoid disappointment.
Suggested limits are based on Joulage Limit rules used Halo Mill: Proving Grounds, with a 350fps limit for Automatic Replicas, 400fps for Semi-Automatic Replicas, and 500fps for Bolt Action Replicas.
Tap the tabs below to open the relevant chart for your replica.
This table should be used for reference, and cannot be used to check one weight against another, as the weight of the BB affects the power.
In order to check if the BB can be used with your replica chronograph using the weight you wish to use and then compare it against the table.
Every time you change weights you will need to re-chrono and check against the table. This is not a conversion chart between weights.
Suggested limits are based on Joulage Limit rules used Halo Mill: Proving Grounds, and is the equivalent of 350fps, using 0.20g BB resulting in an upper limit of 1.14j.
| Velocity | BB Weight (Grams) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| FPS | 0.20 | 0.25 | 0.28 | 0.30 | 0.32 | 0.36 | 0.40 | 0.43 | 0.45 | 0.50 |
| 250 | 0.58 | 0.73 | 0.81 | 0.87 | 0.93 | 1.05 | 1.16 | 1.25 | 1.31 | 1.45 |
| 260 | 0.63 | 0.79 | 0.88 | 0.94 | 1.00 | 1.13 | 1.26 | 1.35 | 1.41 | 1.57 |
| 270 | 0.68 | 0.85 | 0.95 | 1.02 | 1.08 | 1.22 | 1.35 | 1.46 | 1.52 | 1.69 |
| 280 | 0.73 | 0.91 | 1.02 | 1.09 | 1.17 | 1.31 | 1.46 | 1.57 | 1.64 | 1.82 |
| 290 | 0.78 | 0.98 | 1.09 | 1.17 | 1.25 | 1.41 | 1.56 | 1.68 | 1.76 | 1.95 |
| 300 | 0.84 | 1.05 | 1.17 | 1.25 | 1.34 | 1.51 | 1.67 | 1.80 | 1.88 | 2.09 |
| 310 | 0.89 | 1.12 | 1.25 | 1.34 | 1.43 | 1.61 | 1.79 | 1.92 | 2.01 | 2.23 |
| 320 | 0.95 | 1.19 | 1.33 | 1.43 | 1.52 | 1.71 | 1.90 | 2.05 | 2.14 | 2.38 |
| 325 | 0.98 | 1.23 | 1.37 | 1.47 | 1.57 | 1.77 | 1.96 | 2.11 | 2.21 | 2.45 |
| 328 | 1.00 | 1.25 | 1.40 | 1.50 | 1.60 | 1.80 | 2.00 | 2.15 | 2.25 | 2.50 |
| 330 | 1.01 | 1.26 | 1.42 | 1.52 | 1.62 | 1.82 | 2.02 | 2.18 | 2.28 | 2.53 |
| 335 | 1.04 | 1.30 | 1.46 | 1.56 | 1.67 | 1.88 | 2.09 | 2.24 | 2.35 | 2.61 |
| 340 | 1.07 | 1.34 | 1.50 | 1.61 | 1.72 | 1.93 | 2.15 | 2.31 | 2.42 | 2.68 |
| 345 | 1.11 | 1.38 | 1.55 | 1.66 | 1.77 | 1.99 | 2.21 | 2.38 | 2.49 | 2.76 |
| 350 | 1.14 | 1.42 | 1.59 | 1.71 | 1.82 | 2.05 | 2.28 | 2.45 | 2.56 | 2.85 |
| 355 | 1.17 | 1.46 | 1.64 | 1.76 | 1.87 | 2.11 | 2.34 | 2.52 | 2.63 | 2.93 |
| 360 | 1.20 | 1.51 | 1.69 | 1.81 | 1.93 | 2.17 | 2.41 | 2.59 | 2.71 | 3.01 |
Suggested limits are based on Joulage Limit rules used at Halo Mill: Proving Grounds, and is the equivalent of 400fps, using 0.20g BB resulting in an upper limit of 1.49j.
| Velocity | BB Weight (Grams) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| FPS | 0.20 | 0.25 | 0.28 | 0.30 | 0.32 | 0.36 | 0.40 | 0.43 | 0.45 | 0.50 |
| 250 | 0.58 | 0.73 | 0.81 | 0.87 | 0.93 | 1.05 | 1.16 | 1.25 | 1.31 | 1.45 |
| 260 | 0.63 | 0.79 | 0.88 | 0.94 | 1.00 | 1.13 | 1.26 | 1.35 | 1.41 | 1.57 |
| 270 | 0.68 | 0.85 | 0.95 | 1.02 | 1.08 | 1.22 | 1.35 | 1.46 | 1.52 | 1.69 |
| 280 | 0.73 | 0.91 | 1.02 | 1.09 | 1.17 | 1.31 | 1.46 | 1.57 | 1.64 | 1.82 |
| 290 | 0.78 | 0.98 | 1.09 | 1.17 | 1.25 | 1.41 | 1.56 | 1.68 | 1.76 | 1.95 |
| 300 | 0.84 | 1.05 | 1.17 | 1.25 | 1.34 | 1.51 | 1.67 | 1.80 | 1.88 | 2.09 |
| 310 | 0.89 | 1.12 | 1.25 | 1.34 | 1.43 | 1.61 | 1.79 | 1.92 | 2.01 | 2.23 |
| 320 | 0.95 | 1.19 | 1.33 | 1.43 | 1.52 | 1.71 | 1.90 | 2.05 | 2.14 | 2.38 |
| 330 | 1.01 | 1.26 | 1.42 | 1.52 | 1.62 | 1.82 | 2.02 | 2.18 | 2.28 | 2.53 |
| 340 | 1.07 | 1.34 | 1.50 | 1.61 | 1.72 | 1.93 | 2.15 | 2.31 | 2.42 | 2.68 |
| 350 | 1.14 | 1.42 | 1.59 | 1.71 | 1.82 | 2.05 | 2.28 | 2.45 | 2.56 | 2.85 |
| 360 | 1.20 | 1.51 | 1.69 | 1.81 | 1.93 | 2.17 | 2.41 | 2.59 | 2.71 | 3.01 |
| 370 | 1.27 | 1.59 | 1.78 | 1.91 | 2.03 | 2.29 | 2.54 | 2.73 | 2.86 | 3.18 |
| 380 | 1.34 | 1.68 | 1.88 | 2.01 | 2.15 | 2.41 | 2.68 | 2.88 | 3.02 | 3.35 |
| 390 | 1.41 | 1.77 | 1.98 | 2.12 | 2.26 | 2.54 | 2.83 | 3.04 | 3.18 | 3.53 |
| 400 | 1.49 | 1.86 | 2.08 | 2.23 | 2.38 | 2.68 | 2.97 | 3.20 | 3.34 | 3.72 |
| 410 | 1.56 | 1.95 | 2.19 | 2.34 | 2.50 | 2.81 | 3.12 | 3.36 | 3.51 | 3.90 |
Suggested limits are based on Joulage Limit rules used at Halo Mill: Proving Grounds, and is the equivalent of 500fps, using 0.20g BB resulting in an upper limit of 2.32j.
| Velocity | BB Weight (Grams) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| FPS | 0.20 | 0.25 | 0.28 | 0.30 | 0.32 | 0.36 | 0.40 | 0.43 | 0.45 | 0.50 |
| 250 | 0.58 | 0.73 | 0.81 | 0.87 | 0.93 | 1.05 | 1.16 | 1.25 | 1.31 | 1.45 |
| 260 | 0.63 | 0.79 | 0.88 | 0.94 | 1.00 | 1.13 | 1.26 | 1.35 | 1.41 | 1.57 |
| 270 | 0.68 | 0.85 | 0.95 | 1.02 | 1.08 | 1.22 | 1.35 | 1.46 | 1.52 | 1.69 |
| 280 | 0.73 | 0.91 | 1.02 | 1.09 | 1.17 | 1.31 | 1.46 | 1.57 | 1.64 | 1.82 |
| 290 | 0.78 | 0.98 | 1.09 | 1.17 | 1.25 | 1.41 | 1.56 | 1.68 | 1.76 | 1.95 |
| 300 | 0.84 | 1.05 | 1.17 | 1.25 | 1.34 | 1.51 | 1.67 | 1.80 | 1.88 | 2.09 |
| 310 | 0.89 | 1.12 | 1.25 | 1.34 | 1.43 | 1.61 | 1.79 | 1.92 | 2.01 | 2.23 |
| 320 | 0.95 | 1.19 | 1.33 | 1.43 | 1.52 | 1.71 | 1.90 | 2.05 | 2.14 | 2.38 |
| 330 | 1.01 | 1.26 | 1.42 | 1.52 | 1.62 | 1.82 | 2.02 | 2.18 | 2.28 | 2.53 |
| 340 | 1.07 | 1.34 | 1.50 | 1.61 | 1.72 | 1.93 | 2.15 | 2.31 | 2.42 | 2.68 |
| 350 | 1.14 | 1.42 | 1.59 | 1.71 | 1.82 | 2.05 | 2.28 | 2.45 | 2.56 | 2.85 |
| 360 | 1.20 | 1.51 | 1.69 | 1.81 | 1.93 | 2.17 | 2.41 | 2.59 | 2.71 | 3.01 |
| 370 | 1.27 | 1.59 | 1.78 | 1.91 | 2.03 | 2.29 | 2.54 | 2.73 | 2.86 | 3.18 |
| 380 | 1.34 | 1.68 | 1.88 | 2.01 | 2.15 | 2.41 | 2.68 | 2.88 | 3.02 | 3.35 |
| 390 | 1.41 | 1.77 | 1.98 | 2.12 | 2.26 | 2.54 | 2.83 | 3.04 | 3.18 | 3.53 |
| 400 | 1.49 | 1.86 | 2.08 | 2.23 | 2.38 | 2.68 | 2.97 | 3.20 | 3.34 | 3.72 |
| 410 | 1.56 | 1.95 | 2.19 | 2.34 | 2.50 | 2.81 | 3.12 | 3.36 | 3.51 | 3.90 |
| 420 | 1.64 | 2.05 | 2.29 | 2.46 | 2.62 | 2.95 | 3.28 | 3.52 | 3.69 | 4.10 |
| 430 | 1.72 | 2.15 | 2.40 | 2.58 | 2.75 | 3.09 | 3.44 | 3.69 | 3.86 | 4.29 |
| 440 | 1.80 | 2.25 | 2.52 | 2.70 | 2.88 | 3.24 | 3.60 | 3.87 | 4.05 | 4.50 |
| 450 | 1.88 | 2.35 | 2.63 | 2.82 | 3.01 | 3.39 | 3.76 | 4.04 | 4.23 | 4.70 |
| 460 | 1.97 | 2.46 | 2.75 | 2.95 | 3.15 | 3.54 | 3.93 | 4.23 | 4.42 | 4.91 |
| 470 | 2.05 | 2.57 | 2.87 | 3.08 | 3.28 | 3.69 | 4.10 | 4.41 | 4.62 | 5.13 |
| 480 | 2.14 | 2.68 | 3.00 | 3.21 | 3.42 | 3.85 | 4.28 | 4.60 | 4.82 | 5.35 |
| 490 | 2.23 | 2.79 | 3.12 | 3.35 | 3.57 | 4.02 | 4.46 | 4.80 | 5.02 | 5.58 |
| 500 | 2.32 | 2.90 | 3.25 | 3.48 | 3.72 | 4.18 | 4.65 | 4.99 | 5.23 | 5.81 |
| 510 | 2.42 | 3.02 | 3.38 | 3.62 | 3.87 | 4.35 | 4.83 | 5.20 | 5.44 | 6.04 |














