Caliber:  5.56 NATOBarrel Length:  16 inchesBarrel Profile:  M4Barrel Steel:  Chrome Moly VanadiumBarrel Finish:  PhosphateChrome Lining:  NoMuzzle Thread Pattern:  1/2″ x 28Twist Rate:  1 in 7″Barrel Extension:  M4Gas System Length:  CarbineDiameter at Gas Block:  .750″Gas Block Type:  F-marked Front Sight BaseMuzzle Device:  A2 -styleReceiver Material:  Forged 7075-T6Receiver Type:  M4Handguard Type:  M4 with heat shieldsBolt Material:  Carpenter 158 SteelBolt Carrier Profile:  Full AutoFire Control Group: Panther Polished Trigger (PPT)Grip:  A2-styleStock:  M4-styleBuffer Tube Length:  CarbineBuffer Tube Diameter:  Mil-specOverall Length:  32 inchesWeight (as configured):  6.8 lbsBackup Sight: Magpul MBUS Rear Sight, Black