The ETS pistol mag is made of 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 model fits standard MP5 mag pouches and couplers, works with the ETSCAM-RIFLE speeder loader, and 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.