RC1647 GMT Alpinist Style Case Black Chapter Ring - Steel
- In stock, ready to ship
- Inventory on the way
The RC1647 is the black-chapter-ring GMT Alpinist — built for the Seiko NH34 GMT movement, with an engraved GMT bezel and a black inner compass ring rotated by the bi-directional secondary crown. A scratch-resistant flat sapphire crystal sits over the top. 41.3mm without the crown (43.2mm with), 12.5mm thick, fits a 28.5mm dial — a rugged, travel-ready base for a true GMT build.
Quick specs
| Diameter | 41.3mm (without crown) / 43.2mm (with crown) |
| Lug-to-lug | 46.4mm |
| Thickness | 12.5mm (solid cover) / 12.7mm (sapphire cover) |
| Lug width | 20mm |
| Material | 316L stainless steel |
| Finish | Brushed steel, engraved GMT bezel |
| Crystal | Flat sapphire |
| Chapter ring | Black (inner compass, rotated by the bi-directional secondary crown) |
| Crown | Dual-crown (main + bi-directional GMT crown); 5.9mm × 3.7mm |
| Movement fit | Seiko NH34 GMT movement |
| Dial fit | 28.5mm |
The case includes:
1. Brushed steel case with engraved GMT bezel
2. Pre-installed flat sapphire crystal
3. Installed black chapter ring
4. Sterile dual-crown (main + bi-directional GMT crown)
5. Slim case cover (Solid or Sapphire — your choice)
6. 20mm spring bars
Matching bracelets (sold separately):
1. SB1244 Seiko Alpinist (SARB017) Jubilee Bracelet – Steel
2. SB1245O Seiko Alpinist (SARB017) Oyster Bracelet – Steel
3. SB1245P Seiko Alpinist (SARB017) President Bracelet – Steel
Buying options: Case Cover — Slim Solid Case Cover, or Slim Sapphire Case Cover (shows the movement; added cost).
Compatibility: Built for the Seiko NH34 GMT movement and a standard 28.5mm dial. The bi-directional secondary crown drives the inner compass ring. Fits any 20mm strap or bracelet. See all movements.