Only for usgi mags with black or green follower - Magpul AR Rifles Magazine Follower, 223 Rem

Works great on usgi mags that have a black or green follower, the spring on these fit into the magpul followers the usgi mags with a tan follower have a wider spring and these will not seat properly on that spring. The USGI mags with tan followers are the newer updated mags and the tan follower is already anti-tilt.