Allen Engineering AEM2 (Black, Ops 14th Model). 5.56mm CQB suppressor. Adds only 2.75" past the brake (~4.25" from muzzle). Designed for minimum overall weapon length. Fits barrels as short as 11.5" with standard low-profile gas block, or 10.5" with tapered gas blocks. Compatible with standard AE/OPS brakes and collars. 7-10 turns for best fitment. 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