I have some called Level-Air.
http://www.rvtowingtips.com/level-air.htm
It appears the company is now out of business. But, the link above gives you the idea...
When I had my trailer, I did use them, though it was a toss up on how big of a pain in the butt they were. Yes, they were stable, but still I had to drag out a means of inflation, and time wise... Wood was quicker. I used them when we went to a new or unknown spot, and used wood when we were in our regular spot.
In Hindsight, not sure I would spend the money again, although the ones I bought were I think $75.00 a piece, still enough. Mine at least look a bit more heavy duty than the pics of the "RV Pillo"
I still have them, just can't seem to bring myself to trow out $150.00 worth of stuff... And don't use them with the MH now.
If anyone is interested, make me a deal, the are a bit on the hefty side, I would say at least 10lbs a piece.
John