OPTIMAL OPERATION ON VERTICAL WALLS, DO NOT REMOVE THE CORE, WHICH ACTS AS A MEASURING CAP FOR THE COOLANT. USE WITH WATER COOLING EXTENDS THE USEFUL LIFE OF THE TOOL. THE THIN-WALLED DIAMOND RING GUARANTEES BURR-FREE CUTS. THIS FEATURE FACILITATES DRILLING WORK ON HARD TILES IN PLACE, WHERE IT IS NECESSARY TO MAKE A CLEAN HOLE.