Metal body from a G&G ARP556 Comes with hardware Fits V2 gearbox set up for M4 No cracks There is some material removed from the front of the upper, likely for a certain rail system The only thing missing is a small spring for the bolt catch, it's not a functional bolt catch anyway so it serves no functional purpose, without the spring it just sits a little loose against the body You will not be able to use the selector switch unless you have one of the newer G&G gearboxes that have the extra hole where the selector gear/cam meshes with the selector plate The extension on the back of the lower is short on these as they're designed for PDW stocks, you may not be able to mount a normal buffer tube with a sling plate The mock bolt isn't shown but it is included