For this automatic version, Vintro Watches have chosen a special clockwork mechanism with a great and long tradition. The Sea-Gull ST1940 is based on an old Swiss model, the Venus 175, originally developed and manufactured by Fabrique d’Ebauches Venus SA in Moutier between 1940 and the early 1960s. It was used in several high-end chronographs, such as the Breitling Chronomat and the Breitling Top Time Chronograph. In the 1960s, Venus decided to develop a new clockwork mechanism that would replace the 175. To raise the required capital, the company sold all the rights and tools needed to manufacture Venus 175 for the Chinese military, who then produced clockwork mechanisms for their air force. Later, this mechanism was commercially marketed as the Sea-Gull ST19 series. The calibre ST1940 used is a modified automatic version – a precise, reliable, and modern clockwork with a ratchet wheel. Due to the tradition and origin of the ST1940, it has the robustness and accuracy of the Venus 175, which is why Vintro Watches chose it for this watch.