Machined from a black anodized aluminum; Provides an Aimpoint T1-T2 mounting surface that fits to most vented rib shotgun barrels; Mount will also accommodate Vortex Crossfire, Sig Romeo 5, Holosun 403/503, and other like red dots; Geometry of this unit attaches directly to a vented rib 6-10mm wide; Great for turkey, waterfowl and upland bird hunting; Does not fit Benelli 20 gauge rib