The 41.5 mm diameter Constant Force Tourbillon 11 watch in 18-carat yellow gold, released by Arnold & Son as a limited edition of 11, is driven by a hand-wound mechanical movement. Equipped with two barrels to give a 100-hour power reserve, this timepiece was entirely developed and built at the manufacture in La Chaux-de-Fonds. It is fitted with a constant force mechanism visible on the enamel dial and is regulated by a tourbillon that can be seen on the back.