Up for sale is an ultra rare and highly desirable vintage Casio Cosmo Phase DW-3400 men’s digital astronomy sports watch, powered by Module 830 and produced for the Japan Domestic Market (JDM) during the 1980s. This is one of the rarest and most collectible models in Casio’s legendary Cosmo Phase series, featuring a distinctive stainless steel case design and an incredibly unique astronomical display that represents Casio’s innovative approach to digital watchmaking during the 1980s.

The watch features Casio’s fascinating astronomical display, which covers the years 1901 through 2200 and provides a visual representation of planetary positions within the solar system. This highly unusual feature makes the Cosmo Phase one of the most interesting and technologically ambitious digital watches Casio ever produced.

The watch is in full working condition, and all features and functions are operating properly, including the iconic astronomical display.

All parts of the watch are original aside from the strap, which has been replaced with an aftermarket genuine Casio black resin strap, as shown in the photos.

The watch has visible signs of use and age consistent with a vintage timepiece from the 1980s. The photos best describe its physical condition and should be reviewed carefully by interested buyers.

Key Details:

* Brand: Casio

* Model: Cosmo Phase DW-3400

* Module: 830

* Era: 1980s

* Market: Japan Domestic Market (JDM)

* Features: Astronomical display (1901–2200), calendar, digital timekeeping, alarm, stopwatch

* Case Material: Stainless steel

* Strap: Aftermarket genuine Casio black resin strap

* Condition: Full working condition with visible signs of use and age

An exceptionally rare and highly collectible vintage Casio digital watch, celebrated for its remarkable astronomical display, futuristic design, and unique place in Casio’s history of experimental digital watchmaking. The DW-3400 remains one of the most distinctive and desirable models in the legendary Cosmo Phase collection.

Ships carefully. Feel free to message me with any questions.