Material: torch ring aluminum, type 6063TS. Plastic spacerPOM Hexagon screw: steel, type 22 Allen key: steel, type 45 Precision machined aluminum with a black anodized matte finish Mounting base With hexagon screws for attachment to the Picatinny / Weaver rail Cleverly adjustable diameter for use with a wide range of flashlights Universal clip-on torch ring With plastic spacer: For torch diameters 23.6 mm to 24.2 mm Without plastic spacers: For flashlight diameters 25.4 mm to 26.0 mm