TimberTech CONCEALoc is a stainless steel fastener exclusively designed for the TimberTech grooved decking product line. TimberTech has partnered with Tiger Claw to develop a proprietary system that delivers a fast and easy installation process that allows for a clean, superior, fastener-free deck surface. TimberTech CONCEALoc Fastener - box of 175 installs with a standard drill/driver. Each box of 175 fasteners includes Stainless Steel screws and a #1 square driver bit. CONCEALoc Hidden Fasteners are designed exclusively for use with TimberTech grooved decking. The use of other hidden fastener systems with TimberTech grooved boards may damage the board or result in the boards not being adequately fastened to the joist system.