Replacement gearbox for all Elite Force M4 CQB Series AEG Rifles. This high quality Version 2 gearbox comes fully built and ready to drop-in your favorite AEG, and features a high-tension CFR Spring and Micro Switch trigger. The integrated Quick Change Spring System makes it simple and easy to upgrade or replace the spring mechanism within this gearbox.

Features:

• Version 2 Gearbox
• High Tension CFR Spring
• Micro Switch Trigger
• Full Metal Reinforced Tooth Piston
• Quick Change Spring System
• Reinforced Tappet Plate