In 2013, Arnold & Son raised eyebrows with their Ultra-thin Tourbillon Escapement “UTTE” watch which, back then, was the world’s thinnest tourbillon watch. The watch was just 8.34mm thick and housed the calibre A&S8200 which measures just 2.97mm thick. Though it has since lost the title of thinnest tourbillon watch to the Bulgari Octo Finissimo Tourbillon…