Compatible with all Large Frame DPMS/SR25 High Profile upper receiversThe CMT UHPR(TM)-HP series of AR10 Rails are designed from the ground up for hard use either in tactical, competition or hunting scenarios.CMT ARCA compatible AR10/SR25 rails offer an integrated ARCA SWISS mounting surface providing the ability to use ARCA compatible tripods without adding additional componets to your rail/rifle. The wider shape profile of the ARCA mounting feature also provides a superior stable surface versus the typical AR10/SR25 handguard shape profile when shooting from a bag rest or a variety of barricade positions.Features Rail- 6000 series extruded Aluminum Milspec Type 3 Class 2 Hard Black anodized Easy installation with included barrel nut wrench. Barrel Nut- alloy steel Black oxided finished 17-4PH Cored Stainless Steel Rail mounting attachment- maximum lock on barrel nut eliminating forward slippage or handguard/rail rotation. includes 1/8" antirotation pin- location shown in pictures. No Barrel nut shims required for installation Does not contact or apply side loads to gas tube Inner Diameter of handguard - 1.420" MLOK Slots at the 3, 6 and 9 o'clock positions Includes barrel nut wrench Barrel Nut diameter- 1.520" Compatible with most known low profile gas blocks Rail weight including barrel nut and mounting hardware- 23.5 ozs. No qd sockets Made & Assembled in USA