Best used to mount plastic foot brace rails common on many makes of kayak. Not compatible with Keepers Slider tracks or other metal rails and tracks. Sold in a four pack. Number 14 (3/16 dia), One Inch long. Coarsely threaded for cutting into plastic hulls and rails. If needed, shorter No. 14 3/4 inch screws (9800415) are also available. Alternative part number is 9820126.