- Complete drop-in Version 2 gearbox
- Integrated electronic trigger system
- Reinforced shell with quick spring change
The CYMA Sport Complete Version 2 Gearbox for M4/AR-15 AEG; Deans is a ready-built internal upgrade or replacement designed for players who want reliable performance without building a gearbox from parts. Pre-assembled at the factory, it provides consistent alignment, dependable shimming, and solid electrical efficiency straight out of the box.
Fitted with an onboard electronic trigger and low-resistance wiring, this gearbox offers improved trigger response compared to standard mechanical trigger setups. The reinforced shell, 8mm bushings, and metal spring guide make it a dependable choice for skirmish rifles needing a durable internal core.
This gearbox is best suited to players upgrading a worn or broken Version 2 gearbox or building a budget performance M4 platform. It is not a high-speed competition build, but it is a solid, reliable foundation that balances cost, durability, and practical performance. Compatibility with Tokyo Marui spec Version 2 parts means future upgrades remain easy.
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
Dispatched with 24hr UK mainland
£8.95
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
Features
- Complete factory-assembled gearbox
- Version 2 M4 AEG compatibility
- Integrated electronic trigger
- Reinforced metal gearbox shell
- 8mm metal bushings
- Quick-change spring guide
- Low resistance wiring
- Rear or front wiring variants
- Deans connector installed
- M120 spring included
- Tokyo Marui spec partsare compatible
- OEM replacement unit
Package Includes
- CYMA Sport Complete Version 2 Gearbox for M4/AR-15 AEG; Deans
Specification
General
Parts & Accessories Type | Electric Internal Parts |
|---|---|
Internal Part Type | Complete Gearbox |
 | |
Name Variant | Rear Wired, Front Wired, |
Part Specific
Part for Power Source Type | Electric |
|---|---|
 | Assault Rifle |
 | Assault Rifle |
Package Includes | Complete Gearbox |
Electric Part Specific
 | V2 Gearbox |
|---|
Motor Specific
 | High Speed |
|---|---|
Motor Shaft Length | Long |
Motor Pinion Type | D-Type |
Size guide
Parts Fitting
Upgrades and Downgrades should only be undertaken by experienced players, or Airsoft Technicians. Please note, changing any internal parts of a weapon voids its warranty unless done in-house by our staff.
Please ensure that when fitting parts the part purchased is the correct part, as once a part has been fitted we cannot accept return.
We do know that players love to tinker, so we're here to give you help should you require it, and if needed you can get in touch with our workshop for more help!
Unique Parts
Please note that some parts may be unique to a specific brand of weapon. For example: Parts for an ASG M4A1 may not fit an ICS M4A1.
Parts from the same brand typically have a high chance of fitting, though be warned, some replicas use unique parts, so please ensure the part will fit before you attempt to fit it.
If you require help with fitting any parts feel free to get in touch with us via our Contact Us Page.
For more information with fitting parts, or should you require help, feel free to get in touch with our Workshop Department via our Contact Us Page.
Terms and Conditions relating to parts fitting can be read on our Terms and Conditions Page.