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JBU Full Metal Version 2 Gearbox FPS Upgrade Kit for M4 AEGs

SKU: ACC-SDJA41 JBUOut of stock

  • 1x M120 Spring
  • 1x Aluminum Steel Teeth Piston
  • 1x Ported Aluminum Piston Head w/ Bearings
  • 1x Ported Aluminum Cylinder
  • 1x Aluminum Cylinder Head
  • 1x Steel Ball Bearing Spring Guide


JBU Full Metal Version 2 Gearbox FPS Upgrade Kit for M4 AEGs

This high quality Version 2 gearbox upgrade kit features a powerful M120 spring, that is sure to raise the FPS of your Version 2 gearbox equipped AEG. Also included in this premium upgrade package is an aluminum, steel teeth piston head, a ported aluminum piston head, a ported cylinder, an aluminum cylinder head, and a steel bearing spring guide. If you want to maximize the performance of your AEG, this is the upgrade kit for you!

Compatibility: Designed for Version 2 Gearbox equipped M16, MK16, and M4 AEGs. Make certain that your AEG is compatible with this upgrade components.

NOTE: Professional installation is recommended/may be required. Airsoft Megastore is not responsible for the installation of these components, or damage to your AEG caused by installing these components. Make sure to check the compatibility of your AEG and your AEG's gearbox with these upgraded internal parts. These components are for full metal Version 2 Gearboxes only!

In the Box


California Proposition 65 Warning: Cancer and Reproductive Harm -

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