The Radian Ultralight QD Endplate, R0078, is machined from billet 7075-T6 aluminum with a Mil-Spec Type III anodize finished. Radian Weapons then press-fits a Titanium QD (Quick Detach) slick swivel cup. This combination of materials and finishes is ideal for weight reduction without sacrificing durability or performance. This Ultralight QD accessory weights a mere 6.5 grams! Compatible with both Mil-Spec and commercial carbine buffer tubes. A castle nut (Not Included) is required for installation.