Torx T20 X 2-1/2 in. L Driver Bit , 2PK, Fastenmaster Cortex, Mfr#: FMCTXSETOOL2PK

The Cortex Hidden Fastening System is the fastest easiest way to hide the heads of your deck screws across the entire deck first and last board perimeter and stairs. Cortex plugs are made from the same material as market-leading deck boards.