This Seiko 4004 dates to December 1975, and according to its serial, it was literally **the** first Seiko produced that month. A small but incredibly cool detail from the decade that changed watchmaking forever. The 4004 line marked Seiko’s transition from the groundbreaking Astron and 38 series into the first generation of mass-produced quartz watches. This was Seiko democratizing quartz timekeeping, and this model represents that moment perfectly. It features a blue sunburst dial that ranges from deep navy to electric blue depending on the light, with that unmistakable 1970s Seiko design language. The watch also comes with the original Seiko bracelet, something you rarely see half a century later. Inside you’ll find caliber 0903, one of the first mass-produced quartz movements to combine accuracy, reliability, and low power consumption at scale. It runs flawlessly at the hallmark 32,768 Hz frequency that set the global standard for quartz watches.  **Condition:** Excellent for its age. The dial and hands are clean, the case shows light wear but remains sharp, and the quartz movement runs perfectly. Please see the pictures for full condition and clarity. Serial dates it to December 1975, being the first Seiko produced that month.  **Case Size:** 37 x 41.5mm stainless steel with a thickness of 12mm and a lug width of 18mm. **Movement:** Seiko 0903, quartz with high-torque stepper motor and a day/date function with quickset. According to the original spec sheet, it was accurate to around +/- 15 seconds per month. Service history unknown, but everything works as it should. **Crystal:** Mineral **Bracelet:** Original Seiko stainless steel bracelet. Will fit a wrist of up to around 7.25 inches. **Price:** Asking $250. Please add $20 for worldwide shipping. Payment methods include Wise, ACH transfer, Revolut, Bitcoin (On-Chain or Lightning), or PayPal G&S for buyers with solid references. Add +6% for currency conversion fees on the latter. I’m located in Portugal, but worldwide shipping isn’t an issue.  Established seller with over 220 transactions – buy with confidence! Make sure to follow me on Instagram (@daily.worn) to check out the newest additions. Happy to answer serious inquiries. No trades, no lowballs. [Pictures](https://imgur.com/a/tArKL9A) [Timestamp](https://imgur.com/a/R6uWk2I)