Night falls on the GPHG-winning Birch

Near Grand Seiko Studio Shizukuishi in northern Japan are areas known for their breathtaking white birch tree forests. The dial of SLGH017 takes the organic birch texture and does it in a subtle black, inspired by the atmosphere of the white birch tree forests on the Hiraniwa Plateau at night.

The Evolution 9 case is beautifully constructed, rendered in High-Intensity Titanium and finished to a high degree with Zaratsu-polished and hairline surfaces. The case also features a lower center of gravity to ensure day-to-day comfort on the wrist.

The eye-catching dial features distinct hour and minute hands, and the hour hand end is shaped to the exact width of the innermost part of the hour indexes. Each hour index is created through diamond cutting, giving them a perfectly flat mirror finish that reflects even the smallest bit of light, enhancing overall legibility.

Inside SLGH017 is the impressive Caliber 9SA5, a 10-beat movement boasting 80 hours of power reserve and a precision rate of +5 to -3 seconds a day. It fetaures three important developments: Grand Seiko's Dual Impulse Escapement, free-sprung balance, and horizontal gear train.

Exterior

• Case Material: High-intensity titanium
• Glass Material: Box-shaped sapphire crystal
• Glass Coating: Anti-reflective coating on inner surface
• Case size: Diameter 40mm × Thickness 11.7mm
• Clasp type: Tri-fold clasp with push button release

Movement

• Caliber: 9SA5 (Hi-Beat Automatic 36,000 vPh)
• Dual impulse escapement (more efficient energy transfer)
• Horizontal gear train (slimmer than Grand Seiko's existing Hi-Beat calibres)
• Grand Seiko free-sprung balance (more shock + friction resistant)
• Power reserve: 80 hours
• Accuracy: +5 to -3 seconds per day (when static) / +10 to -1 seconds per day (normal usage accuracy)

Functions

• Water resistance: 10 bar
• Magnetic resistance: Equipped
• Other details / Features:
• Exhibition caseback
• 47 jewels
• Stop seconds (hacking) hand function
• Date display