Citizen Tsuki-yomi BY1010-81L Men's Watch • Super Titanium • Moon Phase & Radio Controlled

The Citizen BY1010-81L from the Tsuki-yomi collection represents a technological world first. As the first analog, light-powered radio-controlled watch with integrated moon phase calculation, this men's watch combines astronomical precision with state-of-the-art radio technology.

The case and bracelet are made of high-quality Super Titanium, which is extremely scratch-resistant and feather-light thanks to the Duratect TIC surface hardening. The structured blue dial is protected by an anti-reflective sapphire crystal and reflects the aesthetics of the moon's surface.

Special Features of the Citizen BY1010-81L Watch

• Innovative Moon Phase Calculation: The watch daily calculates and precisely displays the exact position of the moon based on received radio signals.
• Super Titanium Case: The patented material is five times harder than stainless steel, particularly skin-friendly, and offers unparalleled wearing comfort.
• Eco-Drive Light Drive: Battery changes are never necessary, as the watch is charged by any light source and has a high power reserve.

Watch Care Instructions

Care & Cleaning

• Daily: Wipe the case and strap with a soft, dry cloth to remove dirt and sweat.
• Water-resistant watches: Clean with mild soapy water and a soft brush, rinse, and dry thoroughly.
  Important: Screw the crown down tightly beforehand!!!
• Not waterproof: Clean only dry or slightly damp, do not use water or cleaning agents.
• Avoid: Abrasive 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 when showering or bathing, have it checked annually.
• Battery (Quartz): Have a dead battery replaced immediately.
• Mechanical watches: Service every 5 years by a master watchmaker.

Storage & Handling

• Store the watch separately, not directly with other jewelry (risk of scratches).
• Remove mechanical watches when winding, do not leave the crown pulled out.

Jewelry Care – How to keep your jewelry beautiful:

• Remove jewelry before showering, bathing, and sports.
• Avoid direct sunlight – wood, leather & co. can fade.
• Hands off – constant touching leaves grease and dirt.
• No aggressive cleaning agents such as chlorine, salt water, or disinfectants.
• Apply cosmetics and perfume first, then put on jewelry.