Features:<br />--Can be used with a standard electric drill.<br />--Always use lubrication (water)， otherwise the diamond core drill will burn.<br />--Materials and only needs water for lubrication.<br />--This diamond coated core drill bit removes a complete circle from glass， marble，  tiles，granite， ceramic or other.<br /><br />Specifications:<br />Size: 6mm/0.23"， 8mm/0.31"， 10mm/0.39"， 12mm/0.47"， 15mm/0.59"， 16mm/0.62"， 18mm/0.7"， 20mm/0.79，22mm/0.86"，30mm/1.18"<br />Material: steel<br /><br />Use note:<br />Start your hole diagonally， make a round trace and then hold drill straight.<br /><br />Package includes:<br />3 set Diamond Hole saw(30pcs)<br />