Dura-Ace FC-R9200 chainrings are constructed with high quality aluminum and are compatible with FC-R9200 and FC-9200-P 2x 12-speed cranksets.Features-Aluminum with anodized finish provides durability and light weight-36t inner chainring is for use with 52t outer chainring-Asymmetric 110 BCD-Compatible with HG 12-speed chainsItem Specifications-Color:Black-Ring Position/Type:Inner-Tooth Count:36-Round or Oval:Round-Drivetrain Speeds:12-Chainring BCD:110 Asymmetric-Material:Aluminum-Defined Color:Black