Description
SEIKO Prospex Speedtimer HBC003J
The SEIKO Prospex Speedtimer HBC003J is a mechanical sports watch inspired by the functional styling and distinctive colours of classic motor cars. Its ice-blue dial is paired with a black inner rotating ring and orange accents, creating a highly legible, instrument-inspired appearance.
Although it belongs to the historic Speedtimer series, the HBC003J is not a chronograph. Instead, it features a countdown scale on an internal rotating ring. The ring is operated by the crown at the 4 o’clock position and can be used to monitor remaining time during motorsport activities or everyday tasks.
Ice-Blue Dial with Motorsport-Inspired Accents
The pale ice-blue dial is complemented by a contrasting black countdown ring and orange details. The orange seconds hand coordinates with the markings on the rotating ring, improving visibility when timing short intervals. Applied hour markers and broad hands give the dial a bold and practical appearance.
Internal Countdown Ring
A separate crown positioned at 4 o’clock rotates the internal countdown ring. This function allows the wearer to set a remaining-time reference for activities such as race starts, service intervals and other timed events without using a conventional chronograph mechanism.
Calibre 6R55 Automatic Movement
The watch is powered by SEIKO’s Calibre 6R55 mechanical movement. It supports both automatic and manual winding and provides approximately 72 hours of power reserve when fully wound. The movement operates at 21,600 vibrations per hour, uses 24 jewels and includes a stop-seconds function for precise time setting.
Compact Stainless-Steel Sports Case
The stainless-steel case measures 39.5mm across, 44.5mm from lug to lug and 12.0mm thick. SEIKO’s DiaShield surface treatment improves resistance to everyday scratches. A curved sapphire crystal with an anti-reflective coating on its inner surface provides durability and clear dial visibility.
Multi-Row Stainless-Steel Bracelet
A finely articulated multi-row stainless-steel bracelet is designed to follow the shape of the wrist for a secure and comfortable fit. It uses a push-button three-fold clasp and a C-ring adjustment system.
Key Features
- SEIKO Prospex Speedtimer mechanical model
- Ice-blue dial with black and orange accents
- Internal rotating ring with countdown scale
- Countdown ring operated by the crown at 4 o’clock
- Automatic Calibre 6R55 with manual winding
- Approximately 72-hour power reserve
- 21,600 vibrations per hour and 24 jewels
- Stop-seconds function
- Stainless-steel case and multi-row bracelet
- DiaShield surface coating
- Curved sapphire crystal with inner anti-reflective coating
- LumiBrite on the hands and hour markers
- 20-bar water resistance
- Magnetic resistance of 4,800 A/m
- SEIKO Global Brand Core Shop model in Japan
Specifications
| Brand | SEIKO |
|---|---|
| Collection | Prospex |
| Series | Speedtimer |
| Model Number | HBC003J |
| International Reference | HBC003J1 |
| JAN Code | 4954628473189 |
| Release Date | 5 September 2026 |
| Japanese Distribution | SEIKO Global Brand Core Shop model |
| Target | Men |
| Display | Analogue |
| Watch Type | Mechanical three-hand watch with countdown inner ring |
| Movement | Automatic with manual winding |
| Calibre | 6R55 |
| Accuracy | +25 to −15 seconds per day |
| Power Reserve | Approximately 72 hours when fully wound |
| Frequency | 21,600 vibrations per hour / 3Hz |
| Jewels | 24 |
| Movement Functions | Stop-seconds function |
| Timing Function | Internal rotating ring with countdown scale |
| Chronograph | No |
| Dial Colour | Ice blue with black and orange accents |
| Case Material | Stainless steel |
| Case Coating | DiaShield / super-hard coating |
| Case Dimensions | 44.5 × 39.5 × 12.0mm |
| Case Diameter | 39.5mm |
| Lug-to-Lug | 44.5mm |
| Case Thickness | 12.0mm |
| Weight | 154g |
| Crystal | Curved sapphire crystal |
| Crystal Coating | Anti-reflective coating on the inner surface |
| Luminous Material | LumiBrite on hands and hour markers |
| Water Resistance | 20 bar / 200 metres |
| Magnetic Resistance | 4,800 A/m |
| Case Back | Screw case back; orientation may vary between individual watches |
| Bracelet Material | Stainless steel with DiaShield coating |
| Clasp | Three-fold clasp with push-button release |
| Distance Between Lugs | 20mm |
| Maximum Wrist Size | 205mm |
| Bracelet Adjustment | C-ring system |
| Country of Origin | Japan |
| Warranty in Japan | 3-year manufacturer warranty |
| Limited Edition | No limited-production quantity announced |