The cover keeps the trolling motor and prop from cutting a hole in your boat tarp during transport. This complete cover protects the motor as well as the tarp. There is an additional webbing liner inside the cover for increased protection from the trolling motor prop. The cover will fit up to a 12" trolling motor prop and is 19" in length. It is also designed for the trolling motor prop to be positioned on the inside of the boat vs. the outside.