Shimano Cassette Washer 9/10/11V Mountain Bike & Road Bicycle 9S 10S 11S For Thickness 2.56mm/2.35mm/2.18mm
The flywheel washer is a flywheel fitting, part number 5 (C washer) as shown, not a washer for use between the base and the flywheel, be sure to distinguish it clearly.
Shimano flywheel washers have three thicknesses, 11-speed 2.18mm, 10-speed 2.35mm, 9-speed 2.56mm. Flywheel washers of the same thickness can be replaced with different models, for example, 9000 flywheel washers can be used on other road or mountain Shimano 11 speed flywheel. 7900 flywheel washer is not black (color shown).