The Kasper 600 watch movement is part of a group of calibres that include the Aurore-Villeret 120, Bulova 6AH, and FHF 120. These calibres are equivalent and have interchangeable parts, although there are contradicting records regarding their interchangeability. The Bulova calibres display design differences compared to the FHF calibres, suggesting that the ebauches may have originated from Aurore-Villeret. It is worth noting that there are no known differences between calibres 120, 123, 132, and 172, suggesting that these designations likely refer to different plate shapes. The Kasper 600 movement is a manual wind movement, available in both sweep seconds and non-sweep seconds variations. It was commonly used around the year 1945.