Made of black anodized aluminum this housing fits all Mark 32 binoculars (Anchor Optics, National Inst, Universal Camera), and the Bausch & Lomb 7X50 binoculars up to Mark 27. The housing is 40mm long by front outside diameter 63mm inside diameter 60mm. The rear threaded end outside diameter is 58mm and the inside diameter is 55mm. Beauty ring slides right over these housings for a perfect fit. The beauty ring is 33mm wide by 63mm inside diameter and 65.5mm outside diameter.