Specna Arms Complete Reinforced Gearbox V3 (AK) with Micro-Contact

Specna Arms
  • Complete gearbox
  • Version 3 for AK replicas
  • Enter and Convert quick change spring system

If you are after a well put together complete gearbox which won't break the bank, you have found one! The Specna Arms Reinforced Gearbox with Micro-contacts is a complete V3 gearbox with a reinforced shell, 8mm bushings, and a microswitch trigger pre-installed. This gearbox sports all of Specna's usual gearbox enhancements, as well as 18:1 ratio steel gears, giving this gearbox the speed to outrun any competitors in this price range!

Full description


The complete gearbox V3 from Specna Arms is a ready to go solution for anyone with a nice AK replica with a dead gearbox or anyone in the process of custom building their own AK AEG. If you have ever had the *shudders* pleasure of going inside an AEG gearbox, you will understand why Specna offering this as a complete unit is a massive time and headache saver!

The gearbox shell sports reinforcements in all the key areas the venerable version 3 gearbox design is known to fail, including above, below, and in front of the cylinder window, and surrounding the gearbox spine. These reinforcements serve to prolong the life of the gearbox should you choose to use it in a DMR build with a stronger spring or a high rate of fire build. The gearbox also sports 8mm bushings which help keep the AEG running efficiently with minimal wear and maximum longevity.

The internal components present in this complete gearbox are as follows: 8mm bushings, polymer quick-change spring guide, reinforced steel 18:1 gears, Type 0 cylinder, dampened cylinder head, air sealed piston head, polymer piston with a steel final tooth, and a polymer air nozzle. A respectable spec list, if we do say so! In fact, unless you are going for something really at the cutting edge of Airsoft performance, this setup will fulfil almost any requirement for a practical skirmish AEG which is built to last!

The trigger system within this gearbox is a micro switch trigger, providing improved trigger response and electrical efficiency when compared to standard copper contacts. This means you can spam the semi-auto all you want, without the risk of arcing causing corrosion on the trigger contacts. The gearbox is fitted with a standard AK style trigger, AK selector plate, and top cover latch, meaning you won't need anything extra other than your motor, and motor cage!

This gearbox is available in two different wiring configurations; wired to the rear, which is ideal for AK AEGs with space for a battery in their stock, and top wired, intended for use in AK AEGs with a folding stock with their battery stored under the top cover. The pre-installed battery connector is a Mini-Tamiya, allowing you to make use of the most prevalent batteries in the Airsoft world without the need to re-wire!


  • Reinforced shell
  • M110 Spring installed
  • 8mm bushings
  • Rear or Top wired to Mini-Tamiya connector
  • Enter and Convert quick change spring system
  • Reinforced 18:1 steel gearset
  • Micro-switch trigger
  • Wiring extension included
  • Excellent internal spec - Far better than rivals in this price range!

Package Includes

  • Specna Arms Complete Reinforced Gearbox V3 (AK) with Micro-Contacts - Rear Wired

Special instructions

The spring installed in this gearbox is rated at 110m/s and should give around 400FPS when installed in an AEG with good air seal. Bear in mind that this is above UK legal skirmishing velocities, and unless you are intending to lock this gearbox to semi-automatic it will need a velocity downgrade in the form of a weaker spring before it is skirmish ready.



Internal Part Type
Complete Gearbox
Name Variant
Top Wired, Rear Wired,

Weight and Dimension

Weight KG Icon
Weight (KG)
Approx. 0.454kg


Colour Wheel Greyscale
Item Colour
Construction Icon
Alloy shell with steel gears, various aluminium and polymer internal components
Internal Part Construction
Polymer, Alloy, Steel, Aluminium, Rubber,

Part Specific

Part for Power Source Type
Weapon Platform
  • AK Platform
  • Long Gun
  • AK47
  • AK74
  • AKS74U
Package Includes
Complete Gearbox

Electric Part Specific

Gearbox Icon
Gearbox Version
V3 Gearbox
Gearbox Version Compatibility Variant
Version 3

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.