Brand new QTL sure grip bushing N-4-3/8, split thru the taper and flange to provide a tight clamp on the shaft. The bore measures 4.375" in diameter, and has a 1" keyway with a 3/4-10 threaded hole for a set screw. The flange takes four 7/8-9x8 cap screws which are included. Overall length of the bushing is 8.