Product details:

Shimano developed a unified (standard and compact gearing use the same interface), 4-arm asymmetric crankset spider design for the 11-speed cranksets. For the Dura-Ace Hollowtech II R9100, the rings are designed with Hollowglide construction, which creates a tremendously stiff, lightweight chainring that can withstand daily riding by top level cyclists, as well as the power of the Di2 front derailleur. The teeth are highly engineered for optimal shift efficiency, chain retention, and wear, employing the Hyperdrive tooth profiling system.The R9100 outer chainring features the Black-Pewter anodized fade polished finish and is sculpted to perfectly match the face and finish of the crank spider for make create a near seamless visual experience.Chainring BCD: 110 Shimano Asymmetric
Drivetrain Speeds: 11
Material: Aluminum
Ring Position/Type: Outer