As important as any watch can be too the efficacy of a brand, the 6309-7040/9 is a perfect delivery of intention. It's as rugged and hard wearing as it is aesthetically satisfying. Even as the first "Turtles" released in 1976 turned 41 this year, one thing is certain... they don't get old. This example from June of '81 is no exception. Completely original aside from a replacement crystal, it's an opportunity to add an icon to your roster. One of the last to be constructed entirely in Japan before case production was moved to Hong Kong, it carries the signature Suwa logo just above the 6 o'clock marker. The luminous material has begun to develop a creamy patina, and the unpolished case still bears the original factory finishes. Due to is concave design, the bezel insert has been well preserved and aside from a blemish near the 10 minute marker, it shows little in the way of its 36 years of use. The crown and case back screw down tightly, and the 6309 they protect is a workhorse movement ready to provide many more years of service. A rich olive green, heavy two-piece NATO provides a rugged but refined finish for one of our favorite Seiko tool watches.

Clockwork Synergy Olive Green Heavy Two-Piece NATO with Brushed Hardware (clockworksynergy.com)

Serviced 10/1/17