Timex print ads show His-and-Hers waterproof watches displayed side-by-side, both named Marlin. This is a waterproof ladies from the 50s, and is felt to be a Marlin model. This is one tough watch, with a thick case, and a heavy screw-down back. It has an inner dust cover I have yet to see on any other men's Timex watch! Chrome-plated case, luminous hands and hours, sweep seconds hand. Movement is # 22, and this one runs well. Measures 26.5 mm diameter without crown, 11 mm thick.