Detailed Product Description Universal drill ( multi drill ) PATENT NO. ZL 01 3 11605.3 Can be used for:Iron, stainless, copper, aluminum, steel (4mm ... '', 13/16'', 7/8'', 1''3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 25mm - Our company is ...