FailZero 6mm ARC Bolt Carrier Group Steel. All critical parts are coated with EXO Nickel Boron technology that provides permanent dry lubricity extreme durability and increases both wear and corrosion resistance. EXO Nickel Boron makes for easy cleanup and will improve the performance of your rifle. Specifications for FailZero 6mm ARC Bolt Carrier Group: Manufacturer: FailZero Color: Silver Finish: EXO Nickel Boron Fabric/Material: Steel Bolt Material: Steel Caliber: 6mm ARC Gun Make: AR Platform Gun Model: M16 Hand: Right Features of FailZero 6mm ARC Bolt Carrier Group 6mm ARC Bolt and Extractor M16 Cut Bolt Carrier Cam Pin Carrier Key Firing Pin Package Contents: FailZero 6mm ARC Bolt Carrier Group What firearm models does the manufacturer say FailZero 6mm ARC Bolt Carrier Group is compatible with? The manufacturer suggests that FailZero 6mm ARC Bolt Carrier Group is compatible with M16FailZero FZ6MMARCNH: 6mm ARC Bolt Carrier Group Steel