Variable Speed also known as Multi Speed Belts have a distinct shape. Multi-Speed belt top widths are usually greater than their thickness. This permits a greater range of speed ratios than standard belts.
Usually cogged or notched on the underside, Multi-Speed belts are specified for equipment which requires changes in driven speed during operation. Multi-Speed belts are specified by Top Width, Outside Circumference, and the required Groove Angle. The groove angle can be measured from the drive pulleys.