Quik Drive WSNTLQ212S Deck and Dock 2 1/2-Inch Screws with Quik Guard Corrosion Protection Twin Threads for Faster Driving Quik Guard proprietary double barrier corrosion protection Nibs under head for countersinking Used in Quik Drive Tools PRO250, PRO300S, 2000 SDS. Free Bit in every box of screws #3 Undersized square drive BIT3SU