These sturdy magazines from SDS are formed entirely from a tough smoke-colored Polycarbonate with a polymer follower and steel spring. The unique criss-cross pattern on these mags gives them additional strength to withstand the rigors of use. These magazines also use an innovative follower system that is molded to fit the magazine body exactly, preventing the follower from tilting and keeping the rounds feeding straight and true. With the polycarbonate body design, these mags glide into the mag well effortlessly and lock in tight.