Premium Shimano 110/4 bcd compatible oval chainrings are designed for Dura-Ace 9100 and Ultegra 8000, but can also be retrofitted to 9000 and 6800 series cranksExpertly CNC machined from 7075 aluminum and type II anodized for a long lasting contruction and finishRamps on big rings are specially configured for combinations: 50/34, 52/36, 52/38, 53/39T - other combinations will work but may require more derailleur adjustment*30T can only work with 46T and special bolt set 46/30. (bolts included with small ring)*32T can only work with 48T and special bolt set 48/32. (bolts included with small ring)Due to special mounting construction, aesthetic bolt covers are not offered for these designs110mm 4-bolt32T7075ALBlackStandardUPC/EAN/GTIN: 5110846003365