The Orient Star M45 F7 Mechanical Moon Phase RK-BT0001S is Orient Star’s classical flagship layout: power-reserve indication, a true mechanical moonphase with pointer-style date, and a semi-skeleton window that shows part of the movement on the dial side. A white dial with Roman numerals and the OS mark that appears under changing light sit under dual-curve sapphire with SAR anti-reflective coating.
Power comes from in-house calibre F7M42 — automatic with hand-winding, hacking seconds, 22 jewels, static accuracy of about +15 to −5 seconds per day and more than 50 hours of power reserve. The updated moonphase presentation uses a deeper blue night sky and sharper stars than earlier Mechanical Moon Phase generations, while keeping the M45 case language collectors expect.
Why you’ll love this moonphase
- True mechanical moonphase — a proper moon-age complication, not a simple day/night disc like many mainline Orient “Sun and Moon” models.
- Three Orient Star signatures on one dial — power reserve, moonphase with date indication, and semi-skeleton movement display.
- In-house F7M42 — Japanese mechanical automatic with hand-wind, hack and over 50 hours of reserve.
- Crystal and case quality — dual-curve sapphire with SAR coating on the front; sapphire exhibition back; SUS316L steel case.
- Two straps in the package — stainless steel bracelet with push clasp as the primary band, plus a crocodile leather strap with push-button trifold deployant.
- Stronger water rating than many dress pieces — 5 bar (50 m) for daily wear with better margin than typical 30 m dress watches (still not a dive watch).
Who it suits
Buyers who want a serious Orient Star complication watch for dress and special occasions, or collectors comparing Japanese moonphase options against Swiss dress watches at a higher price. It is a step above Bambino Sun and Moon and open-heart Helios pieces in finishing, crystal and movement grade.
Technical specifications
- Brand: Orient Star
- Reference: RK-BT0001S
- Collection: Classic M45 F7 Mechanical Moon Phase
- Movement: Calibre F7M42, automatic with hand-winding and hacking
- Jewels: 22
- Accuracy (static): approx. +15 to −5 seconds per day
- Power reserve: over 50 hours
- Functions: hours, minutes, seconds, mechanical moonphase, date, power-reserve indicator, semi-skeleton dial aperture
- Case: stainless steel SUS316L; width 41.0 mm; lug-to-lug 49.0 mm; thickness 13.8 mm
- Case back: screw-down exhibition back with sapphire crystal
- Crystal (front): dual-curve sapphire with SAR coating
- Dial: white / silver-tone classical face with Roman numerals
- Bracelet: stainless steel SUS316L, 20 mm, push clasp; wrist range approx. 140–200 mm
- Additional strap: crocodile leather with push-button trifold deployant
- Water resistance: 5 bar (50 m)
- Magnetic resistance: JIS Type 1
- Weight: approx. 145 g (on steel bracelet)
- Origin: Japan
Frequently asked questions
What calibre powers the RK-BT0001S?
Orient Star F7M42 — an in-house mechanical automatic with hand-winding and hacking. It offers over 50 hours of power reserve, 22 jewels and static accuracy around +15 to −5 seconds per day.
Is this a real moonphase or a day/night disc?
It is a true mechanical moonphase on the M45 F7 Mechanical Moon Phase platform, combined with pointer-style date and power-reserve indication. That is a different complication class from mainline Orient Bambino “Sun and Moon” day/night models.
What size is the case?
41.0 mm width, 49.0 mm lug-to-lug and 13.8 mm thickness, with 20 mm lugs. It wears larger than the 39 mm M45 Small Second siblings but stays within classic dress proportions.
Does it come with a leather strap as well as the bracelet?
Yes. The primary band is a stainless steel bracelet; an additional crocodile leather strap with push-button trifold clasp is included so you can switch between bracelet and leather wear.
How water resistant is the RK-BT0001S?
5 bar (50 m). Suitable for daily wear and light splash exposure. Not intended for swimming, showering or diving.
Where can I buy the Orient Star RK-BT0001S in Australia?
This listing is available from Chronospride. Stock is authentic, inspected before dispatch, with free shipping Australia-wide on eligible orders. Coverage is Chronospride’s 12 months warranty, handled by our team — see our authenticity and warranty page for full terms.
Authentic stock, inspected before dispatch. Free shipping Australia-wide on eligible orders. Covered by Chronospride’s 12 months warranty, handled by our team. See our authenticity and warranty page.
| Case-Size | 41mm |
|---|---|
| Band-Width | 20mm |
| Lug-Width | 20mm |
| Lug to lug size | 49mm |
| Case Thickness | 13.8mm |
| UPC | 4906006296453 |
| GTIN | 4906006296453 |
| EAN | 4906006296453 |
