Conforms to RMA Engineering Standard Comparable to Gates, Browning, Goodyear, Dayco, Bando, PIX, Bestorq, Grainger Timing belts are measured by Length, Tooth Pitch, then width. The first number is the length, the letter (and sometimes number) refer to the tooth and the final number is the width. Some are measured in mm and others in inches. If you are not matching a belt number, you should contact us for clarification prior to an order. Jason D800H-100 Double Sided Timing Belt, Belt Length: 80.0 in, Pitch Code: H, Width: 1.00 in, No. of Teeth: 160, Approx. Weight: 0.75 lbs