Offered here is a rare Longines chronograph, circa 1960-1970s, powered by their Cal. 13ZN predecessor – the 30CH. This example, the Reference 7413, is fitted in a large, steel case, and features a screwback waterproof layout, and pump pusher chronograph buttons. This Longines chronograph is in excellent vintage condition. The case is unpolished and sharp, with original bevels in the lugs, and not a tool mark to the caseback in sight. The sunburst dial is in great condition, with no wear/flaws.