The Shanghai LB20 is an automatic mechanical calibre produced in China, used in annual calendar style replica references. It carries five hands alongside a multi-complication display: a day and month window at 12 o'clock, a moonphase sub-dial with date track at 6 o'clock, and a 24-hour indicator — replicating the complication layout of the Patek Philippe Nautilus Annual Calendar 5726 reference. All displayed complications are driven by the movement and functional under normal operation. Detailed technical specifications — including diameter, jewel count, and beat rate — are not publicly documented for this calibre.
In replica watches, the Shanghai LB20 is used specifically in Nautilus Annual Calendar style references where the combination of day, month, moonphase, and 24-hour display is required simultaneously on the dial. The day and month appear together in a dual aperture window at 12 o'clock — consistent with the 5726 reference layout. The moonphase at 6 o'clock tracks the lunar cycle and must be set correctly on first wear and after extended non-wear. The movement features an exhibition caseback, making the automatic mechanical assembly visible from the rear.
In Practice
- The day and month complications advance automatically — the day advances daily and the month advances at the end of each month. Both are visible simultaneously through the dual aperture window at 12 o'clock, consistent with the Nautilus 5726 dial layout.
- The moonphase complication at 6 o'clock tracks the lunar cycle and is functional — it advances automatically and displays the current moon phase. After extended non-wear or a battery change, the moonphase requires manual resetting. As with all mechanical moonphase indicators in this production tier, periodic manual correction maintains accuracy over time.
- The 24-hour indicator is functional and advances continuously alongside the main timekeeping — it provides a day/night reference readable from the sub-dial area at 6 o'clock alongside the moonphase display.
- The exhibition caseback reveals the automatic movement in operation. Unlike skeleton references where the movement is visible from the front through an open dial, the LB20's mechanical assembly is accessible only from the rear — the dial side presents the full complication display without exposing the movement architecture.
- The Shanghai LB20 is not widely documented in technical databases — detailed specifications including diameter, jewel count, and beat rate are not publicly available for this calibre. It is a relatively obscure Chinese movement used in a specific reference context rather than a broadly distributed calibre with established community documentation.
Related Terms
Mingzhu DG5866PB V2 · Sea-Gull ST1655 V3 · Miyota 6P00 · Super Clone · Sapphire Crystal
Read Next
For a full overview of movements used in replica watches — including how the Shanghai LB20 compares to other complication calibres — read: Replica Watch Movements Explained