Agile-shop 2Pcs 38mm Glass Drill Diamond Hole Saw Tile Ceramic Glass Porcelain Marble Drill Bit Tool This diamond coated core drill bit removes a complete circle from glass, tiles, marble, granite, cer Can be used with a standard electric drill(Excluding in this item) Easy to use, high quality,good performance, long life - Excellent for making clean and accurate hole Always use lubrication (water ), otherwise the diamond core drill will burn - Start your hole diagon