This V-belt transmits power from the combine's engine drive system to the straw chopper input shaft. It sits in a single-groove pulley arrangement on the chopper assembly, coupling the rotational speed of the drive pulley to the chopper rotor. A worn or slipping belt reduces chopper rotor speed, leading to uneven straw distribution behind the machine. The belt's cross-section and length match the original pulley geometry so that tension and wrap angle are maintained without shimming or additional idler adjustment. On installation, check pulley alignment and tension the belt to the manufacturer's specification to prevent slip under load.