Rugged steel, phosphate-treated magazine stands up to the harsh conditions of combat and competition. Self-lubricating polymer follower and heat-treated, precision-wound spring delivers 20 rounds of ammo reliably and consistently. Steel floorplate easily removes for cleaning. Fits DPMS Panther LR series rifles (.243, .260, .308 caliber), Knight's Armament SR-25, Remington R-25 (.308), and Stoner SR-25. Will not fit Armalite AR10. Mfg: Pro Mag SPECS: Steel, heat treated, black oxide finish, polymer follower, 20-round capacity. 55/8 long. Fits DPMS Panther LR series rifles (.243, .260, .308 caliber), Knight SR-25, Remington R-25 (.308), and Stoner SR-25. Does not fit the ArmaLiteA(R) AR-10A(R), Rock River Arms, or any rifle usin