PPS STS - Shock Transfer System for M4 Rifles

This is a shock transfer system (STS) from PPS (SHS) that is designed to transfer the impact of the piston on the front of the gearbox to the body of the gun. This greatly reduces the stress on the front the the gearbox which commonly causes V2 gearboxes to fail. This part is mounted in front of the gearbox surrounding part of the hopup unit and is stabilized against the gun body. It features two adjustable pins which can be set to just apply a slight back pressure on the gearbox so that the impact force can be transferred effectively. This combined with a few other modifications like sorbo and radiusing can stabilize even the weakest stock gearboxes against heavy springs in high velocity guns. Note: Due to the variances in many brands of guns there is a chance this will not fit perfectly, notable G&P guns had problems with using STSs which I'm not sure have been fixed by SHS. Slight modifications are needed to fit VFC M4s due to an additional spring for the ejection port bolt.

Specifications:
Material: Aluminum
Use: M4 series of rifles (see note)