Features:* * Made of material, and practical to use * Saw blade reduction ring, inner hole conversion ring, cutting disc inner hole reduction ring, easy to use with saw blade rail and electric grinder.* Can be used in conjunction with rotary tools for cutting metal, wood, plastic, etc.* For adjustment and conversion, alloy saw blades and other mounting holes become smaller. Suitable for saw, marble blade inner hole conversion, angle grinder, cutting machineSpecifications:* Material: Iron* Color:Silver(As pictures show)Main Specifications: inner diameter O.D. (in mm)25.4-1622-1625.4-2020-1622-2030-25.425.4-22*High hardness, not easy to break. Good cutting effect, flat and smooth cuts. Package Contents:1Pack x Washer (1 Pack = 10pcs)Note:1. The actual colors of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.2. Please allow slight manual measurement deviation for the data.