Check the listing for details. RC Ohlins TTX 22 Nitrogen / Oil Free piston O-ring set. Condition: New. Listed at 16.00 USD. RC TTX 22 free piston O-ring sets come as 2 red / 2 purple o-rings, they replace the Ohlins OEM Buna o-rings that often fail within 15 hours of use.Free piston rings must be swapped during every service interval. Ohlins spec 20 HR. of use. Sold in pack of QT.4.Works Orings are made by Racers Choice for the Ohlins TTX22 cartrige free piston. These rings are specially made and are propriatary.These updated rings have been proven to last twice as long as the OEM ones and often exceed 30 hours before failure.Red ring is installed at top "nitrigen side" and purple ring is installed at bottom "oil side", lubricate upper ring and nitrogen cavity with an apropriate O-ring grease.We also offer the rings in bulk packs of 10 red / 10 purple "20 total rings" for Ohlins suspension techs.Designed / Made by Racers Choice Suspension.