The Box Four chain employs an 8-speed platform in a similar strategy to the Prime 9 but at a great price point. The chain is polished and then chemically treated to achieve corrosion resistance. We engineered the inner link spacing to be a little tighter than other 8-speed chains and is optimized for use with our Box Four Wide/Narrow Chainring. 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?