The Windham Weaponry 20 round magazine is manufactured to the highest possible standards to offer you the utmost in reliability, performance and durability. They incorporate the best Magpul Gen III self leveling follower featuring a four way anti-tilt design with spring stabilizers on top of a 17-7 PH stainless steel spring. The 6061-T6 aluminum magazine box is black Teflon coated inside and outside. A Windham Weaponry Logo stamped base plate is removable for cleaning. Made in USA.