Package Includes: 1 Set Diamond Coated Hole Saw Drill Bits Size: 11Pcs:6/8/10/12/14/16/18/20/22/25/30 15Pcs:6 /8/10/12/14/16/18/20/22/25/28/30/35/40/50mm Features: 1.This product uses advanced natural diamond materia 2.This diamond coated core drill bit removes a complete circle from 3.glass, tiles, marble, granite, ceramic or other materials and only needs, water for lubrication. Please note that: 1.Always use lubrication (water ), otherwise the diamond core drill will burn# 2.Can be used with a standard electric drill or bench drill( Excluding in this item ) 3.Easy to use, high quality,good performance, long life 4.Excellent for making clean and accurate hole on glass , tile and marble 5. Start your hole diagonally, make a round trace and then hold drill straight Note: 1.Please allow 1-2cm measuring deviation due to manual measurement. 2.Due to the different monitor and light effect, the actual color of the item might be slight different from the color shown on the pictures.