Universal rubber belt O-650E The method of purchase triangle belt: Determine the width and thickness of the belt. K type (7.6 mm thick 6mm) M type (width 9.5 mm thick 6mm) Type A (width 13MM thick 8mm) Type B (wide 17MM thick 11mm) C (width 22MM thick 14mm) D type (width 32MM thick 20mm) SPZ type / 3V (wide 9.7 mm thick 8mm) SPA type (width 12.7 mm thickness 10mm) SPB type / 5V type (width 16.3mm thick 13mm) SPC type (width 22mm thickness 18mm) 2. Then determine the circumference, the easiest way is to use a thin rope around the path of the belt (i.e. pulley groove) a circle measure the length, the length is the metric model of belt (belt inside the perimeter model). WARM AND SWEET REMINDERS:If you have the some problem please contact to our customer!.Picture prices for reference only We will be first class quality and service with the best price which is committed to adhere to the quality reputation with brand market share, innovation and development. In order to benefit from the scale of the enterprise policy to get wide product, perfect service.