Mustang Quarter Turn Seat Screw (1/4"-28) Chrome, one-piece steel seat screw is brightly chrome-plated and features a wide, deep radiused slot that easily accepts a quarter or a flat-bladed screwdriver. Raised diamond knurl on the edge. 1/8-inch longer for easier seat installation with saddlebags and luggage racks. Sizes: 1/4 - 20 (for 1996 and newer Harley-Davidson&#174; models) or 1/4 - 28 (for 1995 and older Harley-Davidson&#174; models).