Chinatera 10Pcs 1/8 inch Diamond Coated Drill Bit Hole Saw Core Drills Marble Glass Hole Saw Materials: 100% brand new and high quality metal Size: 3mm Diamond coated hole saw and 2.4mm shank and 53mm total length Features: durable, long service-life, easy to install Uses: suit for use in drill hole on glass, marble, tile or granite Warm Tips: pls add water for coolant and drill slowly