Piston rings for the standard 20754 and 20773 replacement pistons, as typically found in classic Mini 998cc A+ engines. These R33636 rings are the same as the R39400 rings, but are a 4-ring set instead of a 3-ring set for the 20773 pistons. If fitting to a 3-ring piston that takes the R39400's, you can simply keep the third ring as your second ring, which should be of an oil scraper type and usually the top two rings are the same, so one of them can be discarded. Ref: R33636, R33636-00.
Sold as single-piston ring set. Order four (4) for a complete engine rebuild.