Features1Aluminum Alloy: 12 speed cassette is made of aluminum alloy material, which is suitable for various harsh riding environments. Anticorrosion, good heat resistance, and long service life. 2Smooth Rotation and Noiseless Operation: Bicycle freewheel provides smooth rotation and operates quietly, enhancing the overall riding experience. 3Accurate Internal Thread: The high accuracy internal thread ensures a tight connection with the bicycle hub, improving stability and power transfer. 4Hollow Design: Helps to reduce weight and alleviate the burden during cycling. It achieves a good balance between strength and weight, making it easy to install and use. 5Easy to Install: Bike cassette is designed for convenient installation, making it easy for you to replace or upgrade your existing bike freewheel.SpecificationItem Type: 12 Speed CassetteMaterial: Aluminum AlloyWeight: Approx. 839g / 29.6ozPackage List1 x 12 Speed Cassette3 x Sprockets