The New Factory Tavennes 39 watch movement, commonly referred to as the hunter calibre, features a monometallic screw balance for enhanced precision. It is equipped with a Breguet hairspring and demonstrates versatility through the use of different bridge shapes. This movement offers stem winding and setting functionality, along with a sub-second feature. The New Factory Tavennes 39 movement is known to have been in use during the approximate time period of 1940.