Simplicity 1721117SM  Timing Belt, 20mm Wd 7

The purpose of the Belt is to drive smooth movement within your equipment. Belts are most often found within the engine and cutting deck. The belt length and shape varies based on the system, but most are V-shaped or Cogged. The most common signs that a belt needs to be replaced are the appearance of a shiny, glazed, or burned spot on the side wall or if the belt appears brittle or shows small cracks. Before removing a belt during your repair task, make note of its exact routing around the pulley system.