The principle is as simple as it is effective. You step in, pull the curtain up like a skirt and open the tap. The water, in a black water bag, isw armed by the sun. The bag is flat, has a large surface area and shaped
as a ring around the shower site, giving extra privacy. Opening the cold water tap on one side pushes the warm water on the other side up and out of the bag.
A labyrinthine system inthe bag seals prevents the cold and warm water mixing together. The whole thing can be folded up into a package the size of a small, lightweight tent.