This watch brand was founded in 2001 and is named after the 19th-century watch workshop Arnold & Son. It is based in La Chaux-de-Fonds, Switzerland. Formerly a brand owned by The British Masters, it is now part of Prosser Holdings, a subsidiary of Citizen. Some of its signature products include the Longitude and Instrument Collection/Time Pyramid. In recent years, the brand has also focused on complicated watches. Its sister brand is Angelus.