This is a UTG M-Lok offset flashlight ring mount. It is low profile, 3.47" in length, and comes with two inserts to fit 27mm, 25.4mm (1") or 20mm flashlight tube diameters. Includes M-LOK steel locking nuts, screws and Allen wrench for user friendly installation. Features : Black finish Fits M-Lok "Removable offset mount provides 1.83" forward or rearward offset" "Rings 1.12" vertical or downward offset"