This 40-round magazine from ProMag is perfect for AR-15 owners looking for an extra mag.Made of polymer this magazine also features a patented guided roller follower that ensures anti-tilt performance with improved friction reduction.The spring is formed from heat-treated chrome silicon wire for added durability.ProMag AR-15 223/5.56 Magazine w/Roller FollowerFDE Finish40 Round CapacityFeatures an Anti-Tilt Roller Follower Order your 40-round AR-15 magazine online today!Score big savings and fast shipping when you shop our large selection of cheap bulk .223/5.56 ammo for sale.Looking for AR15 Parts? Find great deals on all in-stock AR-15 Rifle Parts available now from the brands you know and trust!