Citizen Promaster Sky AT8390-55E Men's Watch Black • Radio-Controlled Chronograph • Super Titanium

The Citizen Promaster Sky AT8390-55E is a technically sophisticated men's watch designed for use in the air and on the ground. At its heart is the light-powered Eco-Drive calibre H804 with radio synchronisation, automatically aligning itself with time signal transmitters and running indefinitely without a battery change thanks to solar technology. The Super Titanium case measuring 40.5 mm in diameter impresses with its low weight combined with exceptional scratch resistance, courtesy of Citizen's proprietary Duratect surface-hardening technology. An anti-reflective sapphire crystal protects the distinctive multi-layered dial with yellow and red accents, whose sense of depth is reminiscent of cockpit instruments and head-up displays. Water resistance to 10 ATM makes the AT8390-55E a versatile companion for active use. The integrated chronograph with tachymeter bezel completes the pilot DNA of this model. The matching titanium bracelet keeps the overall weight of the watch to a minimum, ensuring comfortable wear on the wrist.

The Citizen Promaster Sky AT8390-55E combines high-performance technology with a distinctive aviator design, appealing to men who seek a robust, precise and low-maintenance timepiece.

Key Features of the Citizen AT8390-55E

• Radio-Controlled Solar Drive: Eco-Drive calibre H804 with worldwide radio synchronisation and a power reserve of 6 months (up to 2 years in power-saving mode) — no battery changes required.
• Super Titanium: Case and bracelet crafted from surface-hardened titanium, lighter than steel and highly scratch-resistant thanks to Duratect technology.
• Chronograph with Tachymeter: Full chronograph function and tachymeter bezel for precise timekeeping and speed measurement — true to pilot logic.

Care Instructions for Wristwatches

Care & Cleaning

• Daily: Wipe case and bracelet with a soft, dry cloth to remove dirt and perspiration.
• Water-resistant watches: Clean with mild soapy water and a soft brush, rinse, dry thoroughly.
  Important: Screw the crown down firmly beforehand!!!
• Not water-resistant: Clean only dry or slightly damp, do not use water or cleaning agents.
• Avoid: Aggressive agents, perfume, cosmetics and heat.
• Leather straps: Do not soak, clean only slightly damp and allow to dry away from heat.
• Water resistance: Do not wear in the shower or bath, have tested annually.
• Battery (quartz): Have a depleted battery replaced immediately.
• Mechanical watches: Service by a master watchmaker every 5 years.

Storage & Handling

• Store the watch separately, not in direct contact with other jewellery (risk of scratching).
• Place mechanical watches on a flat surface when winding, do not leave the crown pulled out.