MBX Buffer Recoil Reduction System for A4 Carbine LengthThe MBX "Patent Pending" Buffer is Designed specifically for Pistol Carbine Caliber. Features an Internal Spring captured within the Buffer to allow for the Buffer Bolt speed to be significantly reduced during the cycling of the Firearm, resulting in an Extreme Reduction with Felt Recoil. Buffer weight 6. 8 ozs Overall length 4. 9 inches Made from Stainless Steel Includes internal . 062 recoil reduction spring Captured Pin Design to ensure reliability