WMD is the premier manufacture of superior nickel boron coated products featuring their proprietary NiB-X finish. This particular item is a matched AR-15 upper/lower forged receiver set with handguard. The upper features M4 feed ramps and a mil-std 1913 picatinny rail. Using this matched receiver set is a great way to start of your next build and the NiB-X coating provides you with a durability not often found on receivers.