They claim it's a Ronda .It looks like a Ronda 763 , there are lots of pictures of the quartz movement on TD websites . Could be a Chinese movement , but can't see why ? You can buy Ronda 763 movements cheaply in bulk probably no more than $8 with a battery ( probably less ) . They used to make them look like genuine Cartier movement made by Ebel ( same shape Cartier stamped etc ) they don't bother now . I wouldn't worry ! Whether it's a cheap Chinese or Swiss movement nobody is looking inside the watch and it's easy to change battery yourself . They look absolutely spot on as a fake on the wrist outside , you just need to change the strap for something nice (lizard/croc) , the rep strap is crap . Also you'll need small wrists if your a man , the 25mm/28mm quartz Tank Solo's are tiny watches, either for ladies or men with twig arms .