Allen Engineering AEM5 (FDE). Direct-fit suppressor for the MK12 SPR. Over-the-barrel design: 8.8" total length, adds only 4.5" past muzzle device. Caliber: 5.56mm. Weight: 21oz. Mounts via external threads on a separate mount (not included) with a collar for barrel alignment. 20-degree taper locks suppressor in place and seals gases. 7-10 turns for proper mounting. Requires minimum 2.5" from barrel end to taper collar start — generally 12.5" carbine gas or 14.5" mid gas barrel minimum. Made by Trajectory Arms under Allen Engineering license. Always verify alignment with a rod before use. Note: If this product is reflected as in-stock it means it's either physically in-stock or allocated and available (serial number is assigned) at my distributor