Smart-Bit Pre-Drilling and Countersinking Tool designed for decking and woodworking. The tool features a pre-set countersink, a free spinning stop collar to protect the work surface and replaceable Powerbolic fluted drill bits that cut through decking more than twice as fast as standard wood bits. Comes with 2 replacement drill bits. They are perfect for use with hardwoods like ipe, mahogany, and meranti. Designed for trim head screws.