9 colors 12'' inch ultralight keymod handguard rail float rail mount systems for ar-15 / m4 / m16 .223/5.56

model no.: nsr-12 //material: t6 6061 aluminum //color choice: ( black / red / blue / grey / glass green / olive green / purple): anodized / ( tan ): printed //length: 12 inch / 305 mm //weight : about 0.39 kg //one piece monolithic rail / one piece //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 ) //a steel barrel nut inlcuded