The Shimano Alivio CS-HG51 8 Speed 11-28 cassette is suitable for hybrids and mountain bikes with eight gears. This cassette uses hyperglide technology for smooth shifting. Made of nickel-plated steel, this cassette is supplied with soder. The weight of this cassette is 281 grams (with the 11-30 version). Product specifications: - Brand: Shimano - Group Shimano: Alivio - Group code Shimano: HG51 - Model code Shimano: CSHG51 - Model year: 2010 - Number of gears: 8 - Type of Shimano: HG - Resistance: 11-28 - Material: steel - Primary base color: gray - Number of speeds: 8 - Compatible body: Shimano - Speed ratio: 11-32