Shimano wide range mountain bike cassette, part of the high performance XT range.

Can also be used with the new Shimano GRX.

SPECIFICATION - 

• Smooth, durable shifting under load
• 12-Speed HYPERGLIDE+
• MICRO SPLINE
• Optimized for durability
• Largest two cogs constructed from alloy
• Smallest ten cogs forged from steel
• Cassette Options: 9-45T and 10-51T