This Box Three chain is polished & then chemically treated to achieve a basic level of corrosion resistance. All Prime 9 chains have chamfered shifting edges, solid plates & solid pins to safeguard durability. Box's unique inner link spacing is engineered to grab those modern wide/narrow chainrings. Box also chose to modernise the 9 speed platform due to the chain's spirited reputation. Compatibility: • Box One Prime 9 11-50T Cassette Black • Box Two Prime 9 11-50T Cassette Black • Box Three Prime 9 Cassette Black • Box One Prime 9 Rear Derailleur • Box Two Prime 9 X-Wide Rear Derailleur Black • Box Three Prime 9 X-Wide Rear Derailleur Black • Box One Prime 9 Shifter Black • Box Two Prime 9 Shifter Black • Box Three Prime 9 Shifter Black FAQ: Is the Box Three Prime 9 Chain compatible with other 9 speed drivetrains? Yes, All Box Prime 9 chains have standard external geometry that will work with most existing 9 speed drivetrains. Is the Box Three Prime 9 Chain Compatible with any wide narrow chainring? No, Box Prime 9 chains are compatible with most 11-speed wide narrow chainrings but there are some chainrings that can result in poor performance. We recommend the following 11 speed wide/narrow chainrings for best performance, Wolftooth Components, Raceface, One Up Components, Absolute Black. How should I clean my Box Three Prime 9 Chain? We suggest removing the chain from the bike & using a soft bristle brush or rag with soapy water or a mild degreaser. We do not recommend pressure washing, strong solvents or de-greasers as they could degrade the surface coating.