Citizen Tsuki-yomi A-T 43mm Eco-Drive Watch #BY1018-55X

Model Reference: BY1018-55X

Overview
The Citizen Tsuki-yomi BY1018-55X is a striking, high-performance addition to the "Moon Reading" collection, specifically released to commemorate the 30th Anniversary of Citizen's Atomic Timekeeping technology. This model stands out for its bold, deep red dial, which features a rich, reddish-purple hue and the collection’s signature lunar-surface texture. Unlike the standard stainless steel models, this version is crafted from Super Titanium™, making it 40% lighter and five times more scratch-resistant than steel. It remains a technical powerhouse, featuring the world’s first radio-controlled automatic moon phase movement.

Technical Specifications

Case Size: 43mm (Sharp, faceted "Super Titanium" profile)

Case Material: Silver-Tone Super Titanium™ (Finished with Duratect hardening technology)

Movement: Eco-Drive (Caliber H874; Radio-Controlled Atomic Timekeeping with automatic moon phase)

Crystal Type: Sapphire Crystal (Superior scratch resistance with anti-reflective coating)

Water Resistance: 100 Meters (10 ATM / 333 feet) — Ideal for swimming, snorkeling, and daily life

Dial: Deep red "Blood Moon" textured dial with black accents and a moon phase window at 6 o'clock

Bezel: Fixed bezel with black ion-plated detailing

Strap: Silver-tone Super Titanium™ link bracelet with a fold-over push-button clasp

Special Features

30th Anniversary Edition: This model celebrates three decades of Citizen's leadership in radio-controlled precision, incorporating the pinnacle of their atomic and lunar technology.

The "Luna Program": By receiving signals from atomic clocks, the watch uses an internal algorithm to calculate the moon's exact phase, automatically rotating the 6 o'clock disc to ensure the display is always perfectly accurate.

Super Titanium™ Construction: Utilizing Citizen’s proprietary titanium treatment, the watch is exceptionally lightweight (approx. 105g) and gentle on the skin (hypoallergenic), while being rugged enough to resist the scuffs of daily wear.

Hemisphere Alignment: Unique to this movement, the wearer can switch the moon phase orientation to match its appearance from either the Northern or Southern Hemisphere.

"Blood Moon" Aesthetics: The textured red dial evokes the rare celestial event of a total lunar eclipse. Under different lighting, the color shifts from a vibrant crimson to a darker, more mysterious purple-red.

Global Atomic Sync: Automatically updates the time and date across four major regions (North America, Europe, China, and Japan) for laboratory-grade accuracy.

Perpetual Calendar & World Time: Features a fully automated calendar (accurate until 2100) and allows for quick time-zone switching across 24 global cities.

Light Level Indicator: A sub-dial at 12 o’clock provides a visual readout of the power reserve and the strength of the light currently being converted into energy.

Modern Luminescence: High-contrast luminous hands and silver-tone indices provide excellent readability against the dark red backdrop of the dial.