C - Products 2065041206CPD: CPDs Duramag line is known their durability, precision, and exceptional build quality. This Duramag 6.5 Grendel magazine is no exception. Its 410 Stainless Steel body holds together many key features: Its Proprietary Liplock design that assures perfect round placement; A Blue, Advanced Geometry Follower for smooth feeding; Durable Teflon-360 coating technology that enhances magazine-wide performance & reliability; and EverFlex anti-fatigue spring technology.