This trick uses a wooden frame, metal chain and a nut & bolt. The chain is dropped into the frame and locked in place using the bolt. The frame is lifted by the chain wrapping around the bolt - then in an instant, the chain is pulled through the bolt and completely free of the frame.
Very easy to perform and extremely baffling.
The frame size is approx 11cm x 10cm x 4cm (4.2" x 4" x 1.6").