SHIMANO RD-M310 ALTUS rear derailleur black

The Shimano RD-M310 rear derailleur is one of the most popular rear derailleurs on the market, thanks in part to its excellent price-to-quality ratio. The derailleur is designed to work with 7- or 8-speed drivetrains. Properties: * Mega Pulley – a larger 15T tension pulley and a 13T guide pulley to reduce grinding and wear, * Smartcage trolley, * advanced Light Action functions, * low-friction pin bushings, * SIS rear indexed shifting system.