A fabric roof stretched over a lightweight frame in a manner similar to an automobile convertible-roof, for the bed of a pickup truck.
The spokes are hinged to a hub on each side, located on the rails halfway between front and back of the cargo box.
Latchable at both ends and foldable to either, when put up it forms an hollow hemispherical rod covering the bed, the highest point of which is (half the bed-length) above the rails.
Light weight: a tenth that of fiberglass caps or tonneau-covers. Easy to put up or down.
Also available in Conestoga style (not fully convertible).
Makes a dandy tent or storage cover, on or off the truck.-- FlyingToaster, May 17 2013random, halfbakery