http://rvsnappad.com/collections/snappad/products/new-snappad-xtra?variant=23711565827&gclid=CJOSiPqytdACFUtufgod_UwLVg anyone bought these and used them yet look pretty neat and effective
The advantage of bigger ones mine our about 2 feet long - (I use 2/6 with layers of plywood on both sides) is that they distribute the weight and the jacks do not settle into the ground or gravel