The Box Three E-Bike Cassette offers high gears with more teeth to withstand the rigors of modern E-Bike riding. Adding an extra tooth to each of the three highest gears provides increased durability and decreased wear by distributing the load over a larger area! The Box Three E-bike cassette draws from both of its Box One and Box Two siblings to create a sensible all-rounder. All cogs are stamped from steel and subsequently, the larger ones are pinned to steel spiders. The main difference here versus Box Two is the use of additional weight-reducing holes on the cogs. SUPPORT MATERIAL Prime 9 Technology™ View Prime 9 Drivetrain Compatibility Manual How is the Ebike variant different? View Prime 9 E-Bike Comparison Chart Why Prime 9? FAQ Please see page 6 of our guide for notes regarding the 2 HG drivers.