To extend cylinder head drills or all tools with shank ø 8, 10, 12 or 13 mm, machine holder ø 10 or 13x30 mm, with 4 clamping screws for secure tool holder, solid design with good concentricity, with shank ø 13 mm with 3 clamping surfaces on the shaft, 3-part in a wooden case, ø 10 mm, GL 80, 125, 250 mm