Inspired by the well known mobius strip (discovered by August Ferdinand Möbius in 1858), an interest in the unusual, and 3D modelling, I created the Twin Rail mobius pendant.A half shell and 3 rails form a bearing-like structure to encapsulate a train of 6mm balls in a mind-warping cage with a twisting, fascinating movement bringing to life the only pendent of its kind in the world.Includes a 4mm loop for attaching to a necklace or leather cord.See the photographs with retro-fitted 31 6mm chrome steel ball bearings... in the bottom photo, the balls have been heated until they 'blue'... check out the video to see how they move by clicking on the little icon below the camera above.Note: this item is the shell alone, you will need to aquire and fit the balls (31 x 6mm or 29 x 1/4 in) as well as a suitable necklace to hang it from, a 3mm leather cord works well.