The A. Schild 661 watch movement is an open face calibre that includes a stop function with a pillar wheel and a glassed spare-parts compartment. These movements are commonly associated with the Leonidas brand, although they may bear the Venus signature, indicating production by Venus, possibly exclusively for Leonidas. The movement offers various functions such as a timer with options for different time intervals, stem winding, a sweep second hand, and both stop watch and timer functions. It is believed to have been utilized around the 1930s.