GRK 772691021694 12/14 by 4-Inch 3/4 Containing 1-Pack Equal to 50 Screws R4 Handypack R4 Bit Table #4 uses T-10, #6 and #8 use T-15, #9, #10 and #12 all use T-25 Self-Tapping, countersinking head, W-cut thread design and Climatek coated Wood, particle board, cement fiberboard, plastic and sheet metal Multi-Purpose screw R4 ISO certified