BERNY AM093M Skeleton Automatic Watch – 40mm, Sapphire Glass, 21 Jewels, Leather Strap, 5ATM

BERNY AM093M Skeleton Automatic Watch – Miyota 8N24, Sapphire, 40mm, 5ATM

The BERNY AM093M is a 40mm skeleton automatic dress watch built around the Miyota 8N24 — a genuine Japanese skeletonised automatic movement manufactured by Citizen’s Miyota division. 21 jewels, 21,600 vph, 42-hour power reserve, hacking seconds. Sapphire crystal. Open-heart dial exposing the running gear train and movement architecture through a cut-out window. Gold-tone bezel and crown. Faux crocodile leather strap with deployant clasp. 5ATM water resistance. 70g.

Key Specifications

Miyota 8N24 — Japanese Skeletonised Movement

The 8N24 is a purpose-built skeletonised automatic movement manufactured by Miyota Co. (Citizen Watch group) in Japan. Unlike movements that are skeletonised after construction, the 8N24 is designed from the ground up as an open-work caliber — the mainplate and bridges are machined with openings to expose the gear train, balance wheel, and escapement as the movement’s primary visual feature.

Key specifications: 21 jewels, 21,600 vph, approximately 42-hour power reserve, automatic bidirectional winding, manual hand winding, and a stop-second (hacking) device. Hacking means the seconds hand stops when the crown is pulled out for time setting — allowing synchronisation to a reference time to the exact second. The movement is available in silver and gilt (gold tone) versions; the AM093M uses the gilt 8N24G, which matches the gold-tone bezel and markers.

The 8N24 is a named, documented Japanese movement used by microbrands and established watch companies globally — a significant step above generic Chinese domestic automatics. It is serviceable by any watchmaker familiar with Miyota calibers.

Open-Heart Dial

The AM093M dial has a vertical stripe texture on the solid dial sections, with an open-heart window cut into the dial face exposing the movement. The balance wheel oscillation and part of the gear train are visible through this window while the watch runs — the defining visual feature of an open-heart layout. Applied gold-tone triangular hour markers and slim hands complete the dial. No date display — the dial reads clean.

Sapphire Crystal

Genuine sapphire glass — Mohs 9 hardness, scratch-resistant under contact with steel, glass, keys, and most everyday abrasive surfaces. A direct material upgrade from the Hardlex glass used in the LONGLUX range. The sapphire crystal is flat-profile, sitting cleanly above the open-heart dial without distortion.

5ATM Water Resistance

Rated 5ATM / 50M — a significant upgrade from the 3ATM on the LONGLUX models. Suitable for splash exposure, rain, handwashing, showering, and swimming. Not rated for snorkelling or diving, and not recommended for high-pressure water entry (diving from height, jet spray). Remove before hot tubs or saunas.

Leather Strap and Deployant Clasp

Faux crocodile leather strap with a deployant (butterfly) clasp — a folding clasp that opens fully for wearing and clicks shut under the wrist for a clean profile. The deployant clasp is more secure than a traditional pin buckle and reduces leather wear at the adjustment holes over time. Maximum wrist circumference 205mm.

How the AM093M Compares

The BERNY AM093M sits in a distinct tier above the LONGLUX skeleton watches: sapphire crystal vs Hardlex, named Miyota 8N24 movement vs Chinese domestic automatic, 5ATM vs 3ATM, deployant clasp vs pin buckle. At 40mm and 70g it is a lighter and more refined dress watch than the heavier OUPINKE skeleton models.

For buyers who want a BERNY with more features, the BERNY watches collection includes models with Miyota 8215, date display, and other configurations. For a higher water resistance or more tool watch character, see the San Martin watches collection.

FAQ

What movement does the AM093M use? The Miyota 8N24 — a Japanese skeletonised automatic movement manufactured by Citizen’s Miyota division. 21 jewels, 21,600 vph, ~42-hour power reserve. It hacks (seconds stops for time setting) and hand-winds. The gilt (8N24G) version is used, matching the gold-tone dial elements.

What is the open-heart window? A cut-out in the dial face that exposes part of the running movement — specifically the balance wheel oscillation and gear train are visible. The movement continues running and the mechanical motion is visible while wearing the watch.

Is the crystal sapphire? Yes — genuine sapphire glass, Mohs 9. Scratch-resistant under normal daily wear. Not the same as “sapphire-coated” mineral glass.

Can I swim with this watch? Yes — 5ATM / 50M is suitable for swimming and showering. Not rated for snorkelling, diving, or high-pressure water entry.

Does the watch hack? Yes — the Miyota 8N24 has a stop-second device. Pull the crown to position 1 and the seconds hand stops, allowing precise time synchronisation.

What is a deployant clasp? A folding clasp that opens fully for putting the watch on and clicks shut under the wrist, leaving no buckle visible from above. More secure and reduces leather wear compared to a traditional pin buckle.

How does this compare to the LONGLUX skeleton watches? The AM093M uses a named Japanese Miyota movement (vs Chinese domestic automatic), sapphire crystal (vs Hardlex), stainless steel case (vs alloy), 5ATM (vs 3ATM), and a deployant clasp. It is a meaningfully higher specification product at approximately twice the price of the LONGLUX models.