Fine-tune the power output of your AEG with the Airtech Spring Shims.

When tuning your AEG, you usually want to maximise the power output while staying within site limits. With so many variables affecting the final muzzle velocity it can be difficult to achieve your target.

These shims are designed to slide onto the spring guide inside the gearbox to create tension in the existing spring. The more shims the more tension and more power.

4 shims of various sizes are included to fine-tune to the required power.

Shim 1 - +5 fps
Shim 2 - +10 fps
Shim 3 - +15 fps
Shim 4 - +20 fps"