Only 1 pc "A" match with CS-M7100 "B" match with CS-M8100, but differ in materials, appearance, finish, size, etc. "B" indicates the part is usable, but differ in materials, appearance, finish, size, etc. Type cassette spacer Brand Shimano MPN Y0GY00310 For Bike Type Mountain Bike UPC Does not apply Part Type Bicycle part .
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