The Core Elite Operations CEO-15 Carbine Buffer Assembly comes with everything you need to complete your buffer system minus an end plate. This kit includes a 7075-T6 aluminum Mil-Spec 6 position buffer tube, a 17-7 Stainless Steel Buffer spring, a 3.23 ounce Mil-Spec buffer, and a 4140 steel castle nut. You can finish this entire buffer tube assembly with an end plate of your choice or one of our CEO-15 QD End Plates.  Our carbine buffer assemblies are built to Mil-Spec standards to ensure smooth and proper function time after time.