I have four of those I am no longer using, for the same reason. I had a stairway I used to get up to my 29' boat when I was working on it, four of those jacks (one on each corner) I could jack it up to roll it around the shop, but have it sitting nice and stable when not.
They are really flimsy and just held together with a big snap-ring, don't plan on doing much with it when they are raising whatever it is off the ground.
