Orient Star M34 F7 Semi-Skeleton “Oboro Pearl” RE-BY0009A | Limited Edition of 200 Pieces, F7F44 Manufacture Caliber, Gradient Mother-of-Pearl Dial and Double SAR Sapphire Crystal (40 mm, 100 m)

Professional Description

The Orient Star M34 F7 Semi-Skeleton RE-BY0009A represents the artistic and technical pinnacle of Orient Star’s Japanese fine watchmaking. Part of the prestigious M34 collection—inspired by the constellation Perseus and nocturnal astronomical compositions—this model, named “Oboro Pearl”, is an absolute collector’s item with a worldwide production strictly limited to just 200 pieces.

The Japanese term Oboro (朧) evokes the ethereal beauty of the subtle, the diffuse, or the veiled. In classical Japanese poetry and aesthetics, oboro describes the mysterious atmosphere of a night when the moonlight shines softly through a fine mist or veil of clouds (oborozuki). Orient Star brings this poetic concept to life through a handcrafted dial made of natural mother-of-pearl (Mother of Pearl) with a smoky gray gradient: an organic surface where iridescence and silvery reflections gently emerge from the twilight, making each of the 200 dials unique and allowing them to interact dynamically with the light.

At the heart of the timepiece beats the in-house F7F44 caliber, a high-end, hand-regulated movement with a chronometric tolerance of +15 to -5 seconds per day and a power reserve of over 50 hours. Its semi-skeleton architecture reveals the oscillation of the balance wheel at 9 o’clock, balanced by a power reserve indicator at 12 o’clock and a small seconds sub-dial at 6 o’clock. Crafted from SUS316L surgical-grade stainless steel with Zaratsu-polished edges, it features a double-curved sapphire crystal with SAR (Super Anti-Reflective) coating, reducing reflections by more than 99% for an unobstructed view of the dial.

Key Features

• The Artistic Concept of “Oboro” (朧): Inspired by the Japanese aesthetic concept of moonlight veiled by mist. The genuine mother-of-pearl dial with a gradient finish recreates an organic play of light and shadow, where the pearlescent sheen subtly appears and fades depending on the angle of the wrist.
• Ultra-Exclusive Worldwide Run (Only 200 Pieces): A numbered commemorative edition with an extremely limited global release, hand-assembled and hand-adjusted in Japan by master watchmakers from Orient Star’s premium division.
• High-Precision F7F44 Caliber (+15/-5 sec/day): In-house automatic movement with 24 jewels, over 50 hours of power reserve, manual winding, hacking seconds, and a standard of chronometric precision superior to that of conventional mechanical calibers.
• Sapphire Crystal with SAR Coating: Double-curved optical crystal treated with a multi-layer SAR (Super Anti-Reflective) anti-reflective coating on both sides, almost completely eliminating unwanted glare and giving the sensation of being able to touch the dial directly with your fingers.
• Flat Sapphire Crystal Exhibition Case Back: A screw-down case back with sapphire crystal (instead of the usual mineral glass) that allows you to admire the mainplate decorated with circular graining, blued screws, and the openworked oscillating weight.
• All-SUS316L Surgical Steel Construction: The case, bezel, and bracelet are crafted from SUS316L steel, offering maximum resistance to wear and salt corrosion, with alternating finely brushed surfaces and mirror-polished bevels.
• JIS Class 1 Anti-Magnetic Protection: Structural shielding resistant to magnetic fields of 4,800 A/m or higher, preventing timing deviations caused by smartphones, computers, or other electronic devices.

Technical Specifications

Component / Feature Technical Detail
Brand and Collection Orient Star (M34 F7 Semi-Skeleton Series)
Reference / Model RE-BY0009A “Oboro Pearl”
Limited Edition 200 pieces worldwide (Limited Edition)
Origin and Manufacture Entirely manufactured in Japan (Made in Japan)
Caliber / Movement In-House Orient Star Automatic Mechanical Caliber F7F44
Chronometer Accuracy +15 to -5 seconds per day
Jewels 24 jewels
Power Reserve Over 50 hours
Case and Bezel Material High-strength SUS316L surgical-grade stainless steel
Case Dimensions Diameter: 40.0 mm | Height (Lug to Lug): 47.3 mm | Thickness: 13.0 mm
Front Crystal Double-curved sapphire crystal with SAR anti-reflective coating
Case Back: Flat, transparent sapphire crystal with a screw-down case back
Dial: Natural gray mother-of-pearl with a gradient finish (Grey Gradation MOP)
Bracelet: SUS316L stainless steel, 20 mm wide, trifold clasp with pushers
Water Resistance: 100 meters (10 ATM / 10 Bar)
Magnetic Resistance Compliant with JIS Type 1 standards (≥ 4,800 A/m)
Total Weight 153 g

Functions and Mechanical Performance

• Power Reserve Indicator: Sub-dial at 12 o’clock with a dedicated hand that monitors the remaining mainspring power reserve in real time (0 to 50 hours).
• Asymmetrical Open Heart Design: Skeletonized window at 9 o’clock revealing the anchor, escape wheel, and balance spring in continuous oscillation.
• Eccentric Small Seconds: Independent subdial at 6 o’clock with concentric guilloché for a smooth and clean reading of the seconds.
• Three-Dimensional Faceted Indexes: Mirror-polished hour markers that channel light toward the center of the dial, crowned by the classic Roman numerals VII–XII at the top.
• Dual-Winding Mechanism: Automatic winding via a high-inertia bidirectional rotor, complemented by manual winding via the knurled crown engraved with the Orient Star crest.