A rock solid all-metal P-mag style magazine for WA and G&P WOCs M4s and other such compatible system GBB ARs. Also fits Inokatsu gas blowback M4.
An ergo design just like P-mags, it even has a removable plate on the bottom which can be added to the top as a cover. While in place on the bottom it is locked down by a spring-loaded catch making accidental removable highly unlikely. The knocker, like many modern magazines, has a roller bearing on it for smoother sailing on your GBB rifles bolt.