The C.E. Smith Company 40 in. Post Guide-Ons 2-Pack are designed to provide clear visual markers to help you transport your boat with ease, whether you're backing up your trailer, or loading and unloading in the water. The 16-gauge square steel uprights provide strength, and are pregalvanized to resist corrosion. The 2-3/8 inch PVC posts enhance durability for lasting use.