This is a new in the package ring set  (complete set of rings for both (2) pistons) for the  1977 1978 1979 1980 1981 Yamaha XS400 motorcycles.  These are the the SOHC (Single Over Head Cam) models and not the later DOHC (Double Overhead Cam models). If you are looking to replace your rings on your stock original size Yamaha piston, then this is the correct part for you.   This is a standard (STD.) ring set.  This has the 2 compression rings and the lower 3pc oil control ring, everything to get your piston compression back where it should be.  Correct replacement for Yamaha part # 2A2-11610-00-00   A great deal!    Get your old bike up and running again. We only sell the best!  Top-quality aftermarket item.  

Correct for 1977-1981 SOHC models:
XS400
XS400E
1980 Special
1981H
1981SH