I seen one at a foundry. It is just a clear plastic bag that attaches to a weighted collar like a dicky. There is a filtered air line attached to a low pressure air supply. Joe
No , the one I had seen 6-7 years ago was made of what looked to be a thin clear polymer tube with a flat end. Sort of like a 2 ½ gallon plastic pail liner that attached to a canvas dickie. The dickie portion had a strap that went over and around the shoulder portion. It had a small hose like a vacuum cleaner hose possibly 1 inch round that supplied air under the bubble to inflate it. The air escaped around the collar. The collar was a ring about 1 inch in diameter possible filed with sand for weight. The clear part was disposable. I am not sure about the collar. Joe
