This multi-rib belt transmits drive from the engine crankshaft to the air-conditioning compressor and other auxiliary components on the host tractor. It sits in the serpentine drive path, engaging the pulleys of the compressor, alternator, and tensioner assembly. A worn or glazed belt slips under load, causing reduced compressor output and inconsistent alternator charging. The manufacturer machines the belt to match the original rib profile and pitch, which maintains proper pulley engagement without requiring tensioner adjustment beyond the standard range.