Compatible with all AR15/M16 rifles Installs the same as factory mag catch Works with original (and aftermarket) mag release button Forever the AR15 has been a right-handed persona**s tool. With Ambi controls evolving, ita**s becoming more of a tool that everyone can use, even left-handed shooters! This Ambi Mag Catch works in place of a standard mag catch to allow left-handed shooters to drop their mag without having to switch to your right hand for the mag release. Easy drop-in replacement, and blends into the style of any AR.