The tungsten carbide-tipped Smart-Bit for fiber-cement board lets users pre-drill and countersink in one step at a consistent depth for smooth finishing. The tool features a free-spinning stop collar, which controls the depth of the drill and countersink. A rubber O-ring around the stop collar prevents surface damage or marking. A built-in debris cavity keeps drilled material from entering the hole. The Smart-Bit for fiber-cement board is designed for use with #10 gauge flat head screws. The tool comes packaged with two different length drill bits, for use with either 5/16- or 5/8-inch-thick fiber-cement board. 800.596.7747.