231.12.42.21.01.001Ref

Unlike traditional watches that utilize a Faraday cage to combat magnetism, the Seamaster Aqua Terra 15,000 Gauss (ref. 231.12.42.21.01.001) uses non-ferrous components to achieve its resistance. This allows the movement to maintain COSC-certified chronometric precision even after exposure to magnetic fields exceeding 15,000 gauss, all while remaining visible through a transparent caseback.