oval 110bcd 4 holes 2x asymmetric shimano 9000/6800

Innovative design allows very small chainring use on 4x110-bcd cranks but a SRAM 12sp or Dura Ace 11sp chain is recommended.Chainrings are sold separately but must be used in 30+46 and 32+48 combinations.Features:Special bolts are included for 30t and 32t inner rings so no additional parts are neededInner and outer oval chainrings are optimized with smooth shifting in mind, (6) up-shifting ramps (outer ring), and (12) down-shifting points (outer ring)Oval rings help the rider spin smoother and generate more powerExample: 32t is equivalent to 30t at dead spot and 34t at the power zoneWorks with 2x chainring systems and does not require any modification to the front derailleur for useCompatible with crank models: Shimano Dura Ace 9100, r9120, r9150 & r9170 di2, Ultegra 8000, r8020, r8050 & 8070 di2., 105 r7000, r7020, r7070, Dura Ace 9000 & di2, Ultegra 6800 & di2, Shimano 105 5800. Not compatible with power2maxDesigned in UK, manufactured in Poland