1. 
   Jack chain
   A jack chain is a type of chain made of thin wire, with figure-eight-shaped links, and loops at right angles to each other. Jack chains are often used to suspend fixtures such as lights or signs, for decorative purposes, or as part of a cable lock. A jack chain is a tool attached to a toothed chain...
   Found op http://en.wikipedia.org/wiki/Jack_chain
   
   

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