These are light weight, easy to use and store. I wish they snapped together instead of just sitting on top of each other. Overall, a lot easier than jacking up and trying to use wood blocks or cement blocks, which require more jacking up to take out and aren't safe. A little pricy for plastic lego's, but it's an RV thing, so of course costs more. They do the job. I don't see them lasting long term, but a simple fix for the now.
Rating: [4 of 5 Stars!]