Shimano Ultegra 6600 10 Speed Road Cassette

• 10 speed Super Narrow HyperGlide compatible cassette
• Fits 9-speed spacing (older 9sp freehubs requires spline shim)
• 6-arm aluminum single-carrier reduces weight & increases stiffness
• 3 largest cogs mounted to carrier: all cogs Nickel-plated steel
• 235g (12-23): Bright polish nickel-plated steel
• NOTE: 13-25, 14-25, 15-25, and 16-27 (junior models) are not compatible with FH/WH-7800 10-speed Dura-Ace freehubs