I saw these a couple months ago. After our last trip with trying to get wood planks under the one side to get the TT level I searched and found these easy to use trailer levelers. I contacted Anderson...
I prefer to dig out a little ground from the higher side to level it out.
Place a 2 x 4 (with blocks on the bottom of each end) across the space where the tires will sit, level on top, scrape the higher side down until level.
Then again, I only really park at my seasonal site, so it's mostly a one and done affair. :)