Shimano Ultegra FC-R8100 chainrings are constructed with high quality aluminum and are compatible with FC-R8100 and FC-8100-P 2x 12-speed cranksets.Features-Aluminum with anodized finish provides durability and light weight-34t inner chainring is for use with 50t outer chainring-Asymmetric 110 BCD-Compatible with HG 12-speed chainsItem Specifications-Color:Black-Ring Position/Type:Inner-Tooth Count:34-Round or Oval:Round-Drivetrain Speeds:12-Chainring BCD:110 Shimano Asymmetric-Material:Aluminum-Defined Color:Black