I don't have a great picture, but on mine for scout camp I used pipe insulation and a piece of plywood. I wrapped the insulation around the edges of the trailer, placed the cut-to-size plywood on top, then secured with 4 ratchet straps, two front-to-back and two side-to-side. Kept out dust and then kept out all the rain we had. Cost me about $25 in total. Plan to stain it to match and figure out a better attachment system. For what it was though, day before leaving, I was pleased.I'm going to try and add a lid to mine that I'll be able to remove by myself. Hopefully I can make it tight enough that it'll keep the goo out but we'll see.