One piece SUS303 cylinder body with EDM precise wire cutting piston rail.  

Enhanced polymer injected piston.

SUS303 anti-twisted spring rotation bearing system.

S45C heat treated EDM wire cutting ladder gear.

SUS303 enhanced nozzle.

All re-design and reinforce NBR rubbers, O-rings.

BCGS (Bolt Carrier Group Sticker) make your PTW more like RS.