[tkwetzel]

I am a mechanic...and those black things between the "legs" and the cart bed are very recognizable. Those are the "airbags" that you hear about it you ever hear about airbag suspension on cars. That is an air tank in the middle of the under carriage. The leg is attached to the cart beyond the airbag at the point that is the origin of the angle between the cart and the leg. The airbag is between the cart bed and the leg and therefore within the angle. By adding air into the airbag and inflating it, it widens the angle and lifts the cart. Each airbag is operateed independently, so you can cause some crazy tilts as seen in the picture.