The ET Arms Inc. Plum Crazy Gen II lower is a carbon infused polymer lower receiver. This is a built out lower with an M4 6-position stock, Nano Composite trigger, and an A2 pistol grip. n nPolymer lowers are fantastic for shaving off additional weight on an AR-15 build, so if you’re trying to put together a fast-handling, general-purpose rifle this Plum Crazy Gen II lower is a fantastic option!! Plus with a price like this, you can’t go wrong! n nThis lower was designed to handle the pressure loads of .223/5.56 NATO, will work with poly and aluminum uppers.