KCI USA Magazine, 9MM, 20 Rounds, Fits HK MP5, Black KCI-MZ041 Fits MP5 variants firearms chambered in 9x19mm. The MP5 line features a stainless steel follower" Reinforced feed lips" and a high carbon steel spring. Encased in a hardened steel body treated with a Cation Electrodeposition coating. The locking plate has been spot welded in four places for added strength.