The Box Three chain is polished and then chemically treated to achieve corrosion resistance. All Prime 9 chains have chamfered shifting edges, solid plates and solid pins to safeguard durability. Our unique inner link spacing is engineered to grab those modern wide/narrow chainrings. We chose to modernize the 9-speed platform due to the chain's spirited reputation. They also work well with BMX 3/32" Chainrings and Cogs. SUPPORT MATERIAL Prime 9 Technology™ View Prime 9 Drivetrain Compatibility Manual How is the Ebike variant different? View Prime 9 Comparison Chart View Prime 9 E-Bike Comparison Chart Why Prime 9?