Sun Race MZ91X Cassette Ultra-Wide Ratio Ultra-wide cassettes are becoming a standard in the mountain bike industry. These make it so you can ditch the front derailleur but still get the wide range. The Sun Race MZ91X Cassette features a wide ratio design and is designed for SRAM XD driver bodies. It has alloy spiders, an alloy lock ring and spacers, and a 7075 alloy 42T - 50T sprocket. At only 560g, this will be your new favorite upgrade. Features Wide-ratio design so you can go from sprinting to climbing with ease Alloy lock ring and spacers as well as a 7075 42T - 50T sprocket Designed for SRAM XD driver bodies Specifications Cassette Body Type XD Driver Body Cassette Cogs10-12-14-16-18-21-24-28-32-36-42-50Drivetrain Speeds12Cassette Material Aluminum Weight560 g | Sunrace | Mz91X Cassette 12-Speed 10-50T | Black Chrome | For Xd Driver Body