JP Adjustable Gas System The JPGS-9D is the minimized small bore design intended to mount underneath many hand guard models on the market. Its two-piece design allows for easier installations even on barrels with pin-and-weld muzzle treatments. This model features the new click-adjustable detent system for precise adjustments and secure retention of your gas screw. Never lose you gas setting or screw. Features: Click-adjustable detent system for repeatable setup and secure retention of gas setting Six clicks per rotation of gas screw for finer adjustments Split yoke design for easy installation even on pin-and-weld barrels Easy to acces Mfg: J P Enterprises