Heavy duty double zippers for main compartment

The goggles are designed in a way to provide full seal protection to protect any projectile from entering the sides

which are 100% co-axial

and a quicker change spring system

ADJUSTERS: POM Thermoplastic

PolarStar F1 Centerline HPA Engine for V2 Gearbox Airsoft Rifles Airsoft Gas Rifle Heavy duty double zippers forM4 M16 What is the F1? Like the Fusion Engine and JACK, the patent pending F1 is a high performance HPA (High Pressure Air) system which replaces the traditional piston and gears of an AEG with a programmable pneumatic system. Flow Control The unique flow control system uses an integral check valve to regulate the forward speed of the nozzle while maintaining the fastest retract speed possible. This system is also what makes the F1's "2 stage" firing