Classical Section V-Belts>These are the original belts used in heavy duty applications. They are specified by cross section and standard length. The size is designated as A, B, C, D or E. The easiest way to select a replacement is by finding the belt number on the worn belt. If not legible, measure the belts outside circumference with a flexible tape,preferably while it?s still on the drive. Then, order the Gates Hi-Power ll V-Belt which has the next shorter standard length. For example: For an ?A?section belt with a 26.0? O.C., order an A24 replacement belt.