High range CT2 technology Minimum clutch Maximum indexing speed The STRONGLIGHT CT2 Shimano Dura-Ace 9100 inner crown is a high range, robust and performance model. Combines 7075 T6 precision machined aluminum and CT2 technology, which consists of a ceramic coating with a layer of Teflon. Ceramic increases durability and anti-abrasion effect. Teflon reduces chain friction by 80%, reduces noise, friction and lubrication and optimises indexing between crowns CT2 crown is durable, lightweight, precise, strong and comfortable. This is proposed in the version for Shimano Dura-Ace 9100 11 speed chainset with 110 mm wheelbase (BCD) - Material: 7075-T6 aluminium - Ceramic coating with a Teflon layer - Compatible with Shimano Dura-Ace 9100 11 speed crankset - Weight (manufacturer): 32 g