Guarder M4A1 BoreUp Full Gearbox Set (Infinite Torque-Up)

A complete Gearbox Upgrade kit includes ALL parts for upgrading your Airsoft Electric Gun AEG 
Guarder made this kit with all suitable parts to super tune up your AEG Rifle 
The combination of difference parts allow an optimal result & performance 
Hard and rigid material used, including S303 Stainless Steel, Brass, Polycarbonate, Aluminum, Acetal and Steel 
100% Made In Taiwan with Top Quality Control making each parts precisely fit 
As always, upgrading AEG require necessary skill & technique to dissemble the gearbox, consult expertise if needed 

Note: Upgrade springs are not included