Stock 40mm replacement rings for a ton of bikes like Honda Hobbit, PA50, NU50, NU50, NA50. Would also work on some Benelli G2 and Batavus M48.
These apparently don't work too well on Yamaha DT50LC so don't buy these for that.
One is a standard ring. The other is a half-keystone ring so pay attention during install- it is for the upper groove.
40mm x 1.5mm - FG