This is an extended CNC machined 303 stainless steel nut that is used to fasten a Mercury centrifugal clutch to a Chrysler West Bend Power Bee 820 engine in a Rokon 2 wheel drive motorcycle. The hex is 11/16″ and the thread is 7/16-20 UNF right hand. It is 3/8″ longer than stock so you do not have to use a special thin wall 11/16″ socket to remove it. This will work with a box wrench or a standard socket. This nut may interfere with the guard on your bike. Check if you have an extra 3/8″ of clearance before you purchase one of these. The Mercury clutch is not included.