The Shimano CS-HG400 8 SPEED 11-40 Acera Cassette is a reliable, durable, and easy-to-install bike cassette with a wide gear range that's perfect for tackling steep climbs and fast descents. Featuring Hyperglide technology, this cassette ensures quick and accurate gear changes even under heavy load, reducing wear and tear on your bike's drivetrain. As part of Shimano's mid-range Acera groupset, the CS-HG400 is an excellent choice for both amateur and professional cyclists looking to upgrade their bike's performance.