The inner blade tip of the 2 blades allow you to drill all compounds such as metal-covered siding and stainless steel upholstered wood (metal + insulation + plywood) with a single stroke. The holes in wood material are good for cutting nails, thin steel plates, metal siding boards, 2 4 (also cutting nails), wood, plywood, PVC board, FRP etc. Blade diameter: 1.4 inches (35 mm) Fits 191 : Electric drill, vibration drill (rotation mode), lightweight hammer drill (rotation mode), blade thickness: 0.1 inches (3 mm), effective length: 6.7 inches (170 mm); Material: Blade part: Carbide chips; Compatible materials: Metal siding board, wood, plywood, thin steel plate, aluminum, galvanized steel plate, 2 4 (also cuts nails), PVC board, FRP, soft siding board, ALC board, gypsum board, stainless steel plate, stainless steel plate, replacement blade core drill core. Le UR-S Shank Product Number: UR25/55FST, UR25/55FSD) Compatible, Body: Carbon Steel, Blade: Carbide Chip