... 4.Diamond tip Zinc plated Diamond glass hole saw for tile,marble,slate Zinc plated Diamond glass & tile hole cutter Diameter from 2mm ... -150mm, Threaded, Straight and round shank, It could be used for glass, tile and stone drilling, The normal total length is 70mm ... —150mm ,it is very easy to use , just add water for lubrication.Pictures: Zinc Plated Diamond glass hole saw for tile,marble,slate