Countersunk Bolt Kit, 1/4-20 in Thread, 1.000 in Long, Hex Drive Head, Countersunk Washers / Nuts, Aluminum / Steel, Black, Set of 10, Kit includes specially designed washers which allow the socket head fasteners to install flush with the surface creating a smooth finished look. Many uses include mounting roofs, side skirts, spoilers and replacing sharp edged fasteners inside cockpit. Kit includes ten washers, bolts and nyloc nuts.