Product Description Shimano lockring for Dura-Ace CS-7900 - lockring in two versions This Shimano lockring is compatible with Dura-Ace CS-7900 10-speed cassettes. There is a version for cassettes whose smallest sprocket has 11 teeth, and a version for cassettes with a 12-tooth sprocket as the smallest sprocket. The aluminium lockring is supplied with a spacer. Technical Information:Material:aluminiumCompatibility:Dura-Ace CS-7900Models:for 11: Application:cassettes w/ an 11 t sprocket as the smallest sprocketManufacturer Number:Y-1YZ98010 12 and up: Application:cassettes w/ a 12 t sprocket as the smallest sprocketManufacturer Number:Y-1YZ98020Contents:1 x Shimano lockring1 x spacer Manufacturer: Shimano Europe B.V. High Tech Campus 92 5656 AG Eindhoven Netherlands info@shimano-eu.com