MK Diamond 157706 MK-290 1-3/4-Inch HSS Premium tile/Marble Core Bit 1 3/4 inch diameter Turbo-style diamond rim Designed to cut clean, smooth holes through all ceramic tile and marble Replaceable pilot drill prevents bit from wandering when starting hole Can be used wet or dry Core bit can be used wet or dry to cut clean, smooth holes in ceramic tile or marble Best used wet to prevent heat build up for deeper holes High speed steel core bit body laser welded to diamond rim provide a top quality, long lasting bit 10 millimeter shank