I use these to support my Golf Cart when I work under it.Unlike many products, they fit back into the box they came in, so they don't hog shelf space when not in use.Another nice thing is the height is continuously adjustable, so you can perfectly level what you are working on if needed.The footprint is sort of small, so you have to put a pad of some-kind under them on warm asphalt of soft ground, that's just common sense on the users part.Had a set years ago when I still worked on my cars, and they got misplaced in a move or "Borrowed", so I was pleased to find them still available.