FLUX DEFENSE Gas Cap for Raider X Flush Stock Black. This addition cuts off the gasses escaping directly backwards from the slide. Easy to install using dovetail slots on the Raider chassis. CAREFULLY CHECK TO SEE WHICH VERSION GAS CAP WILL MATCH YOUR RAIDER Specifications for FLUX DEFENSE Gas Cap for Raider X Flush Stock: Manufacturer: FLUX DEFENSE Color: Black Features of FLUX DEFENSE Gas Cap for Raider X Flush Stock To prevent gas blow back while in SBR form. Package Contents: FLUX DEFENSE Gas Cap for Raider X Flush Stock FLUX DEFENSE 165-00016: Gas Cap for Raider X Flush Stock Black