The major problem with any commercial jack pad is the cost. If they are inexpensive they are generally not stiff enough. I made four pads using two lengths of 2x6 attached to a 12x12 piece of 3/4 inch plywood for each one. Very stiff. I have nylon rope pulls attached to one corner. I also have two one inch thick 12x12 nylon pads also with nylon rope pulls. The nylon pads are very stiff but expensive ($40 each). I use one or more wooden pads any time I think that the ground needs them. I use the nylon pads under the wood pads for winter time parking (four months) at our park in Florida. While the nylon pads were expensive, they get cheaper every year that I use them. They are virtually indestructable.