Designed from day one for the AR15 platform 300BLK was made to utilize many of the most common AR components in existence. With the 12.5 BANSHEE upper group you can build your next 300BLK AR with character like no other. Available in six different Cerakote finishes all CMMG Upper Groups come complete with bolt carrier group and ZEROED accessories including: - ZEROED AR15 Polymer Dust Cover - ZEROED AR15 Ambi Charging Handle - ZEROED Linear Compensator .308 Win - Platform: Mk4 - Caliber: .300 BLK - Operating System: Direct Impingement - Barrel Length: 12.5 - Barrel Twist: 1:7 - Barrel Contour: MR - Barrel Material: 4140CM SBN - Muzzle Device: CMMG ZEROED Linear Compensator - Muzzle Thread: 5/8 x 24 - Gas Port Location: Pistol - Gas Block: 0.750 Non-Adjustable - Upper Receiver: Billet 6061 T6 Aluminum - Hand Guard: CMMG EML11 M-LOK - Finish: Cerakote Standard - Charging Handle: CMMG ZEROED Ambi - Weight: 3.7 lbs - Length: 20.8