I might have to order a pair of these as well, the only thing I can add is that I would want to wedge something simple between the leveler on one tire and the small wedge on the other to be sure it cannot slip out, with kids and dog my TT is always a rocking. As long as one of those little wedges is held tight it will not roll.
I have the yellow blocks and have had them kick up and jam on soft ground and watched my BIL break several of the orange style on soft ground, we could not keep them from kicking up and cracking. I have also broke 2 6 foot treated 2x10's that I used to carry, we go dry camping sometimes and thats where I end up breaking wood.