Specifications for Belt Size 685-5M-18 Cross References Numbers: 685-5M,  685-5M-18,  685-5M/18 Number of Teeth 137 *Length of Belt 685mm or ~27" Peak to Peak Distance Between Two Adjacent Belt Teeth 5mm or ~3/16" Width of Belt 18mm or ~3/4"

*Length of belt is the overall size of the belt's loop measured as if the belt were cut between two adjacent teeth and laid out on a flat surface.