This is the same high quality carbine buffer spring that's found in their complete rifles" complete lowers" and in their various stock kits that they have. It's a Mil-Spec 17-7 stainless steel buffer spring that features an electro polish finish to give it a smoother quality look and feel. If you need a replacement buffer spring or just need one to finish a build" look no further.
Stainless (electro polish) finish
Carbine buffer spring
Mil-spec 17-7 micro polish stainless steel