Description
SEIKO 5 Sports SKX Series SBSA225
The SEIKO 5 Sports SBSA225 brings the familiar design language of the SKX series to a compact 38.0 mm stainless steel case. Created as a mid-size model for the Japanese domestic market, it combines a black day-date dial, a unidirectional rotating bezel and an automatic Caliber 4R36 movement with a stainless steel bracelet.
Compact SKX Series Design
The 38.0 mm case provides a more compact alternative to the larger models in the SEIKO 5 Sports SKX series. Its dimensions of 44.2 mm in length and 12.1 mm in thickness create balanced proportions suited to a wide range of wrist sizes.
The black dial features prominent hour markers, clearly defined hands and a day-date display at 3 o’clock. The Japanese-market calendar uses a bilingual Japanese and English day wheel. LumiBrite is applied to the hands and indexes to support readability in low-light conditions.
Automatic Caliber 4R36
The SBSA225 is powered by SEIKO’s Caliber 4R36 mechanical movement. It winds automatically through wrist movement and can also be wound manually through the crown. The movement operates at 21,600 vibrations per hour, contains 24 jewels and provides approximately 41 hours of power reserve when fully wound.
A stop-seconds function allows the seconds hand to be halted while setting the time. SEIKO specifies an accuracy range of +45 to −35 seconds per day when the watch is worn on the wrist within a temperature range of 5°C to 35°C.
Stainless Steel Construction
The case and bracelet are made from stainless steel. A Hardlex crystal protects the dial, while the bracelet is secured by a push-button three-fold clasp with an additional secure-lock mechanism. The bracelet accommodates wrists measuring up to approximately 205 mm.
The see-through screw case back provides a view of the mechanical movement. The complete watch weighs approximately 140 g.
Rotating Bezel and Everyday Resistance
A unidirectional rotating bezel adds the functional appearance associated with the SKX series. Water resistance is rated to 10 bar, and the watch also features magnetic resistance for everyday use.
Although its design draws from SEIKO’s sports-watch heritage, the SBSA225 is not identified by SEIKO as an ISO-certified diver’s watch. It should therefore not be described as a professional diving instrument.
Japanese Domestic Market Model
SBSA225 is the reference assigned to the Japanese domestic market and is listed in SEIKO’s official Japanese product range. Japanese authorized retail information identifies the watch as manufactured in Japan. The corresponding international model is commonly identified as SRPK29 or SRPK29K1, so the design should not be described as Japan-exclusive.
Key Highlights
- Compact 38.0 mm mid-size stainless steel case
- Black dial with day and date display
- Bilingual Japanese and English day wheel
- Caliber 4R36 automatic movement with manual winding
- Approximately 41-hour power reserve
- Unidirectional rotating bezel
- Hardlex crystal and LumiBrite hands and indexes
- Stainless steel bracelet with secure-lock clasp
- 10-bar water resistance
- See-through screw case back
Product Specifications
| Brand / Collection | SEIKO 5 Sports |
|---|---|
| Series | SKX series |
| Model | SBSA225 |
| International Reference | SRPK29 / SRPK29K1 |
| Market | Japanese Domestic Market |
| Country of Manufacture | Japan |
| Edition | Regular-production mid-size model |
| Watch Type | Mechanical automatic sports watch |
| Display | Analog with day and date |
| Dial Color | Black |
| Case Dimensions | 44.2 mm length × 38.0 mm width × 12.1 mm thickness |
| Weight | Approximately 140 g |
| Case Material | Stainless steel; stainless steel and glass case back |
| Bezel | Unidirectional rotating bezel |
| Crystal | Hardlex |
| Case-Back | See-through screw case back |
| Bracelet | Stainless steel bracelet |
| Band Width | 20 mm |
| Clasp | Push-button three-fold clasp with secure lock |
| Compatible Wrist Size | Up to approximately 205 mm |
| Movement Type | Mechanical automatic with manual winding |
| Caliber | 4R36 |
| Power Reserve | Approximately 41 hours when fully wound |
| Frequency | 21,600 vibrations per hour (6 vibrations per second) |
| Jewels | 24 jewels |
| Accuracy | +45 to −35 seconds per day when worn on the wrist between 5°C and 35°C |
| Functions | Stop-seconds function; day and date calendar |
| Day Display | Japanese and English bilingual display |
| Luminescence | LumiBrite on the hands and indexes |
| Water Resistance | 10 bar |
| Magnetic Resistance | Yes |
| Release Date | May 12, 2023 |
| JAN Code | 4954628465177 |