What metal gadget does Novak Djokovic wear during tennis matches?

Djokovic was questioned about the metal plate after beating Marton Fucsovics at 

human improvement device” that “helps your body realign itself, which leads to a surprising amount of benefits”. 

Italian startup Tao Technologies said he wears a Taopatch, Sky News reported 

Daily Mail reported. He joked that his staff “delivers efficient nanotechnology” 

He was photographed carrying the gadget at the French Open and Wimbledon earlier this year, leaving fans speculating. 

Multiple times, Novak Djokovic has been seen carrying a metal disc on his chest during matches.  

improve his performance. That's definitely my greatest professional secret. If not for it 

Serbian remarked, “I admired Iron Man a lot as a youngster. I strive to emulate Iron Man, 

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