This is a Seiko hand-wound watch, a waterproof (waterproof) model of the Cronos. The seahorse engraving on the back cover is faded at first glance, but can be somehow identified depending on the angle. The regular Cronos has a rather dressy appearance, but this one has thick lugs, giving it a very masculine feel. Since it's non-date, there's no hassle of setting the date, which is nice. The lug width is 18mm. A D-buckle is also included as a bonus. Currently, it's running smoothly with a daily rate of about 1 minute, but since it's an antique that's over half a century old, its operation is not guaranteed. Due to an increase in my collection, I have fewer opportunities to use it, so I am reluctantly putting it up for sale. I believe it will continue to be a great watch, so I will pass it on to someone who will cherish it.