TimberTech CONCEALoc Router Bit is custom-designed for TimberTech to cut a groove in solid deck boards to create a channel to accept a CONCEALoc fastener. This 3-wing cutter has a 1/4" shank to work with any size router and has a high-quality carbide tip to ensure consistent cuts and longer life. With the reconfigured sealed bearings, the Router bit will route right over a joist even after the board has been fastened to the joist to allow for hidden fastening on non-grooved planks.