7/9/10/11/12/13.5/15'' inch m-lok handguard rail ultralight float mount system with 3 pcs m-lok rail sections_black color

model no.: m-lok handguard rail black, nsrcm ultralight m-lok handguard rail material : t6 6061 aluminum color : black anodized length choice : 7 inch / 9 inch / 10 inch / 12 inch / 13.5 inch / 15 inch ( please kindly chose carefully ) rail section length : 3 slots / 5 slots / 7 slots / 9 slots / 11 slots / 13 slots barrel nut : steel barrel nut barrel nut thread spec.: 1-1/4-18 unc barrel nut inside diameter : 1.02'' ( 26 mm) barrel nut outside diameter : 1.35'' (34.4 mm)