“Under The Rail” bed lining is simply what it implies. The Hawaii Spray Liner is sprayed on the inside of your truck bed, and does not extend over onto the upper horizontal surface of your truck‘s rail. Most newer vehicles have plastic rail caps installed at factory. In this case, we recommend an Under The Rail bed liner. If you don’t have plastic rail caps on your truck bed, an Over The Rail bed lining would be a good option to protect the top of the rail. A double coat is unnecessary for the average person who uses the vehicle for transportation and moderate to heavy hauling. Double coats add extra protection for contractors who use their trucks for hauling heavy equipment or for regular construction work.
