Specifications: This diamond coated core drill bit removes a complete circle from glass, tiles, marble, granite, ceramic or other. Materials and only needs water for lubrication. Always use lubrication (water), otherwise the diamond core drill will burn. Works better with a electric drill Start your hole diagonally, make a round trace and then hold drill straight. Item Name: Diamond Coated Hole Saw Drill Bits Quantity: 20Pcs/Set Features: High Strength, Durable, Drilling Tools Size Details: 3/4/5/6/8/10/12/14/16/18/20/22/25/26/28/30/32/35/38/50mm 0.12/0.16/0.20/0.24/0.31/0.39/0.47/0.55/0.63/0.71/0.78/0.87/0.98/1.02/1.10/1.18/1.26/1.38/1.50/1.97 inch Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Included: A Set of Diamond Coated Hole Saw Drill Bits (Total 20Pcs)