Simplicity, compactness and power - Spring Drive in its purest form
SBGA285G is apparently simple, and yet so clever. This Heritage Collection model houses the Spring Drive calibre: an innovative mechanism that combines the drive of a mechanical watch with the unbeatable accuracy of a quartz movement. The refined look is due to the case size of 39mm and the famous, high-quality Grand Seiko finish. For example, the indices have been raised and the black dial has a shine that creates optical depth in an impressive way.
"Automatic spring drive 3-day"
Our company unveiled Spring Drive in 1999, but the lack of a sufficiently effective automatic winding mechanism and a power reserve of 72 hours prevents its acceptance in the Grand Seiko line. After another four years of development, the first Grand Seiko 9R Spring Drive was made.
The winding system and driving time were improved from the existing 48-hour manual winding system to an automatic 72-hour power reserve. The automatic winding mechanism uses Seiko's original Magic Lever mechanism, developed in 1959, but with improved productivity, maintainability and durability to improve winding efficiency.