Wheel Chocks
I made these to help stabilize our trailer. I had a set of commerial versions on my 5th wheel and loved them. Saw a set of homemade ones on the forums and decided to make these. They are made from scrap 4X4 pressure treated fence post scraps, 2 1/2 inch pipe clamps from Harbor Freight ($3.99 each) and 2 pieces of 1/2 inche by 18 inch pipe ($3.30 each at Home Depot).
Here is a picture with all the measurements