Shimano's Deore CS-M7200 12-speed MTB cassette is built around a mixed-material construction: the largest cog uses alloy for weight savings while the remaining cogs use steel for durability and shifting performance. HYPERGLIDE optimized tooth profiles deliver fast, smooth shifting even under load. What Our Gearhead(R) Experts Are Saying:"HYPERGLIDE keeps the shifts fast and clean even when the chain is loaded on a steep climb. The 10-51T range covers everything from technical singletrack to long fire road grinds without running out of gear."