The SunRace Cass10 SP 11-42T is a 10-speed wide-ratio cassette for mountain bikes. This cassette was designed by SunRace and is compatible with Shimano bodies. With a gear ratio of 11-42T, this cassette offers a wide range of gears. The cassette is made of high-quality materials, including aluminum spiders, spacers, and cogset, as well as high-tensile steel cogs 1 through 9 and an A7075 aluminum cog 10. The finish is metallic silver, and the cassette weighs 387 grams. Product specifications - Model: CSMS3 TAY - Gears: 10 (wide ratio) - Function: Fluid Drive Plus - Toothing: 11-42T - Tooth combination: 11-13-15-18-21-24-28-32-36-42 - Material: - Spider, spacer and closing ring: Aluminum - Sprocket 1 to 9: Hi-Tensile Steel - 10th sprocket: A7075 Aluminum / Anodized - Finish: Metallic Silver - Weight: 387 grams