• Compatible with the Saris H3 Direct Drive Smart Trainer, as well as the CycleOps Hammer and H2
• Hyperglide freehub is compatible with Shimano and SRAM 11-speed systems.
• 12-speed systems cannot be used with the H3 Direct Drive Smart Trainer, as well as the CycleOps Hammer and H2.
• The right freewheel body if you want to ride a cassette with the Shimano / SRAM standard on SARIS Direct Drive roller trainers