You will only need to measure one side, both sides will be the same length.

Measure from the mount in front to the mount in back on the same side.

This measurement will determine which model of our product you need to buy.

Our model numbers are 4 digits, the first 2 digits are the longest length for that model and the next 2 digits are the shortest for that model.

As an example, Model # 6458, indicates it will cover any truck with measurements between 64” and 58”. As long as your truck’s measurement falls within the numbers it will fit in your truck.