Designed specifically for use e-mtb drive systems, SRAM's XX T-Type direct-mount rings offer light weight with optimal retention performance needed for e-mtb. Steel and Aluminum construction. Item Specifications: Color: Black/Silver, Defined Color: Silver, Designed for ebike: Yes, Direct Mount Type: Direct Mount Bosch, Drivetrain Speeds: 12, Material: Aluminum, Ring Position/Type: Chain Retaining Single Ring, Tooth Count: 34,