The ETS pistol 10 round mag is constructed of an extreme impact resistance advanced polymer with superior heat, cold and UV resistance, translucent body, and is creep resistant which means the feed lips and body won't spread when being stored long term even when fully loaded. This mag features extremely reliable feeding, even with hollow points. It is far lighter than steel magazines and fits standard MP5 mag pouches and couplers. The mag also works with ETS CAM-RIFLE speed loader. The HK MP5 is compatible with all MP5 style 9mm firearms such as: Zenith, MKE, Omega, POF, HK Contract MP5 9mm Variants, MP5 style SW5, BW5, CA94, D54, V94, clones or other custom builds.