I wanted to expand the uses for my utility trailer and adding the sides and cover to the trailer did exactly that. The sides are made from exterior grade OSB ripped down the middle, giving me 2′ high side walls. It is attached to the metal frame simply by screws through the steel angles. The cover is made from a tarp – custom cut to size with grommets installed along the edge. Screws at the grommets hold the tarp down simply with the tension in the tarp. It got tested in the rain the first weekend I used it and it stayed completely dry inside!