Need for pads/blocks with hydrolic levelers?

I did something similar to Pangaea Ron above --- I cut eight 12 X 12 X 3/4 inch Marine plywood squares then screwed them together and made four jack pads, painted them with several coats of paint, drilled a 3/4 inch hole to retrieve with awning hook and have used them as jack pads for twenty years on three different RV's and they are still just fine ( I often use a 1 foot 6X6 block perched on top reduce the drop on the jacks and thereby firm up the RV).