4-edge Cross Drill Bit Set 7pcsThe ordinary drill bit is easy to damage tile, glass, and other materials when drilling! The four edge cross bit has a concentrated stress point and can drill faster and more accurately without damaging the material. Full range of sizes(3 12mm), faster drilling to meet your diverse needs and improve efficiency. MAIN FEATURES Durable Material: Made of high hardness steel, strong, rust proof, wear resistant, corrosion resistant, and durable. Drill