|Winding:||Automatic, Bi-Directional Automatic Winding|
|Diameter:||25.60 mm (11.5 ligne)|
|Complications:||Big Date, Date, Day/Night Indicator, Double Wheel Big Date, GMT Hand, Independently-Adjustable 12 Hour Hand, Modular|
|Hands:||Big Date at 12:00, Central Hour Hand, Central Minute Hand, Central Seconds Hand, Day/Night Indicator Disc at 8:00, Hour Hand at 6:00, Minute Hand at 6:00|
|Production: 2016 – Current|
Cal. C120 is an automatic movement with big date, independently-adjustable second timezone dial, and day/night indicator. It is produced by Soprod using a module on the Cal. M100 base and was formerly known as Cal. SOP 9351/A10-2. This module adds 1.5 mm to the thickness of the A10-2, bringing the total to 5.10 mm. Like the A10-2, it measures 25.60 mm (11.5 ligne) in diameter.
The big date complication uses dual discs with a pair of windows at 12:00 on the dial. The second timezone dial features both hour and minute hands and sits at 6:00 with the day/night indicator just above this at 8:00.
Seiko Instruments first designed their 4L25 to create an ETA 2892A2 competitor for the Swiss OEM market. Soprod announced their Swiss Made version, Cal. A-10, in 2004 and began offering it to Swiss watch makers. The company was not explicit about the design source of the movement. In 2007, Soprod was acquired by Peace Mark of Hong Kong for the company’s quartz movement operations in China, and the Swiss mechanical operations were sold to Festina Group the following year. Seiko introduced their own 4L25-powered Brightz and Credor models and Soprod continued to produce the A-10 and later the A10-2. The A10-2 was renamed Soprod M100 in 2016.Images are taken from official publications and are used here for commentary and educational purposes. Copyright is held by the original owner as noted.