Quick specs Grand Seiko Evolution 9 Atera Valley Spring Drive SLGA025
Price: $ 10,500 | € 11.100 | £ 9,550 | approx. CHF 9’000
Size: 40 mm
Reference: SLGA025
An emerald-green spring drive driven new model, the Grand Seiko Evolution 9 Atera Valley Spring Drive with reference SLGA025. Of course, the colors of the dial have sprouted from the surroundings of one of Grand Seiko’s Japanese locations. This time from the Nagano Prefecture, where the spring drive watches are manufactured.
Around that (huge) area are lots of mountains rising over 3,000 meters with many rivers flowing in between them. One of them is the Atera River that carves out the Atera Valley with clear, emerald-green waters. Exactly that color has been used on the dial of this Evolution 9, with a watery motif.
The Grand Seiko Evolution 9 Atera Valley Spring Drive SLGA025 has a power reserve of 120 hours / 5 days
Apart from hours, minutes and seconds, the watch has a date at 3 o’clock and a power reserve indicator at the back. So, the back is transparent in order to see the Seiko caliber 9RA2 which drives the Grand Seiko Evolution 9 Atera Valley Spring Drive SLGA025. It is a so called spring drive caliber where the mainspring (two barrels) moves a series of gears.
At the end of these gears is a rotor that generates a small electrical charge. This activates an electronic circuit and quartz oscillator that beats the time, with an average accuracy of ±10 seconds per month.
Is the 9RA2 spring drive movement a quartz?
Is this Seiko caliber 9RA2 a quartz? Yes, but not in the way regular quartz movements work. This is a hybrid taking advantage of the precession of a quartz driven movement, but without batteries. The traditional mechanical part is the source or the engine, the quartz a sort of module that takes care of the hands.
This Atera Valley comes on a stainless steel bracelet with three-fold clasp with push button release. The photo below shows how green water can be in the Atera River.
| Technical data and specifications of the Grand Seiko Evolution 9 Atera Valley Spring Drive SLGA025 |
| Reference number: SLGA025 |
| Movement: Seiko caliber 9RA2 | Automatic spring drive | Diameter: 34 mm | Thickness: 3.4 mm | Frequency: 32,768 Hz | Jewels: 38 | Double barrel | Hours, minutes, seconds, date, power reserve indicator | Power reserve: 120 hours / 5 days |
| Case and dial: 40 mm | Titanium | Thickness: 11.8 mm | Dual-curved sapphire crystal with anti-reflective coating on inner surface | Emerald-green dial with river motif | Steel colored hands and applied indexes | Screw-down crown | Transparent screw-down case back | Water resistance: 10 ATM / 10 bar / 100 meters / 330 feet |
| Strap: Stainless steel bracelet | Three-fold clasp with push button release |
| Price Grand Seiko Evolution 9 Atera Valley Spring Drive SLGA025: $ 10,500 | € 11.100 | £ 9,550 | approx. CHF 9’000 |
| Website: www.grand-seiko.com |