Can be held on using set screws or bolt and washer in end of shaft The easiest way to tell what size chain that you have is to measure between the pins, if it measures 3/8" that is a #35 chain, if it measures 1/2" it would be #41 chain This clutch is for a maximum RPM of 3800, it engages at 2200 RPM ***The clutch does not come with a set screw or key stock. Clutch has 3/16" keyway ***for use up to 6hp***
