JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight Black. 750 Adjustable Gas System And A2-Type Clamp-On Sight is a front sight assembly that replaces existing pin-on assemblies to provide the option of gas adjustment. These AR Gas Blocks from the experts at JP Enterprises can also be used as a front sight only to extend the sight radius of any existing carbine or rifle. Perfect for a competition build this A2 front sight bolts onto a barrel no drilling or pinning required. The JP Enterprises .750 Adjustable Gas System and A2-Type Clamp-On Sight features a sturdy seal to provide better heat dissipation around the gas port as well as an easy-access side gas adjustment. Specifications for JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight: Barrel Diameter: .750" Finish: QPQ Weight: 3.9oz Material: 416 stainless Finish: Black oxide Weight: 3.9oz Length: 1.870" Height: 3.400" (overall) 2.650" (over bore) Width: .870" Attachment: 10-32 x 1/2" socket head screws 5/32 hex drive (includes 5/64" x 5/16" roll pin for gas tube installation): Adjustment: 8-32 x 1/4" stainless set screw 5/64 hex drive (hex key included) Features of JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight: .750 Adjustable gas system A2-type clamp-on sight Package Contents: JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight JP Enterprises JPGS-2FS: .750 Adjustable Gas System And A2-Type Clamp-On Sight Black