This is a very helpful and essential and item if you are restoring or riding a 1980 1981 Yamaha XS850 three cylinder motorcycle.  This is fo 3 full sets of rings (...so enough for  you or your mechanic to complete 1 engine).  These are Standard (STD.) 71.5mm size. Correct replacement for part #3J2-11610-00-00. These are for the stock standard size Yamaha pistons.  Perfect fitment. No disappointments here, we only sell the best! Top quality aftermarket item.  Get your bike up and running nicely again. These sure are fast, fun bikes eh?    We also have complete engine gasket set for this bike. We look forward to doing business with you!