They are replacement rings for the 1370 kit they sell. I had to buy a complete spare set of 6 rings because I broke one of the compression rings in my 1370 kit. I had also sent one of my spare sets of rings to a guy in the states who had also broken one of his 1370 kit rings.
StanG wrote: So, they don't fit on a standard bore, right?
The EBay listing you show is the right fit for a stock cylinder. The same supplier also sells a 64 mm overbore piston kit with 64mm rings.
1980 KZ1300 B2 converting to an A2. Things I'm working on- Body work- Ducktail mod to rear tailpiece. Add a quarter fairing. Paint - House of Kolor Brandywine/Black. Custom decals. Engine- In house custom ground camshafts with adjustable cam sprockets.7 blade rad fan. DG exhaust pipe.