1、With Cooling Wax: Fast heat conduction and large filling volume, the cooling wax inside can effectively transfer heat to prevent drill burning. 2、The Round Shank: The universal round shank is widely compatible with various electric hand drill and angle grinder, which also ensures firm clamping. 3、Diamond Drill Bit: There are 5pcs hole saw and a drill bit made from diamond material, and the stable drilling will improve the work efficiency. 4、5pcs Hole Saw And 1pc Drill Bit: Including 5pcs hole saw of 5mm, 6mm, 8mm, 10mm and 12mm, also has a 5mm drill bit, surely satisfying your working needs. 5、Good Material: Adopting high strength high carbon steel material that has been through excellent workmanship, very easy to deform and durable.