Fast clean cutting core bits designed to be used on hand held drills and variable speed grinders. Suitable for cutting holes in granite and marble up to 40mm thick. The GTS range of core bits are available in diameters 12, 16, 20, 25, 30, 35, 40, 45 and 50mm, with 7mm high diamond segments, 85mm overall length (including M14 female fitting).