WMD Guns NiB-X AR-15 Pistol, Semi-automatic, 223 Rem/5.56 NATO, 10.5 Barrel, 1:7 Twist, Aluminum, Nickel Boron Finish with Red Accent Kit, Free Floating 9 Seekins NOX M-LOK Handguard, 30 Rounds, 2 Magazines, NiB-X Bolt Carrier NIBXARPISTOL-RSR To build an AR platform unlike any other, WMD Guns coated every exterior surface with NiB-X, an exclusive nickel boron formulation. So you get a finish that's 40% harder than chrome, and incredibly resistant to moisture, corrosion, and wear. Key internal components are coated with NiB-X to reduce friction & wear, for an action that's incomparably smooth, utterly reliable, and as close to self-cleaning as you can get.