Sram 7/8speed 34.9mm (35mm) Front derailleur

Sram 7/8speed Front derailleur

42T. Size 34.9mm

"Shifting" in a bicycle, also known as a front chainring or front derailleur, is a part of the bicycle's drivetrain system that functions to shift the chain to different sprockets at the front (on the crank) to change speed and pedaling force.