The Tissot 2403 watch movement is a manually-wound mechanical movement that was utilized during the approximate period of 1965. It shares similarities with the calibers 2480, 2485, 2482, and their Eterna counterparts, 1437 and 1447, but in a mirror-inverted configuration. The minute hand is driven indirectly, enabling a larger balance and a lower profile. The reason for this mirrored variation and the use of these movements in two-handed watches remains unknown.