Seiko Prospex Speedtimer HBC003J Countdown Timer Wristwatch

The Seiko Prospex Speedtimer HBC003J brings the name "Speedtimer" back to its mechanical origins — a watch built around the specific functional demands of motorsport timekeeping, now realised with a countdown timer complication that is both practically useful and visually central to the design. The complication is a countdown-graduated inner rotating ring, operated by the crown at 4 o'clock: turn it to set a countdown duration, and the seconds hand sweeps toward zero against the graduated scale. The application Seiko describes is tyre change timing and pre-race countdowns at motorsport events, but the mechanism works for any countdown scenario where a mechanical reminder is more useful than a digital one. The seconds hand carries an orange accent — a vivid, high-contrast colour that tracks against the countdown graduations at a glance and references the warm amber gauges of classic racing cockpits. The dial colour itself echoes that classic car aesthetic: a muted, vintage-referencing tone that recalls the instrument panels of GT racers from the 1960s and 70s. Caliber 6R55, 72-hour power reserve. Curved sapphire crystal with inner anti-reflective coating. Fine-pitch stainless steel bracelet that conforms closely to the wrist. Dia-Shield case. 39.5mm diameter, 12.0mm slim for a sports automatic. Screw caseback. Core Shop exclusive. Releasing September 2026. Made in Japan. *Pre-Order! Estimated release and shipment from September 2026.* Key Features: Countdown Timer Inner Ring — Mechanical Motorsport Complication: The 4 o'clock crown operates a countdown-graduated inner rotating ring — a mechanical complication that tracks elapsed time against a preset countdown, without batteries or digital displays. Calibrated for motorsport pit stop timing and race start countdowns, but usable in any context where a visible, tactile countdown is useful. The ring is bidirectional and can be set to any duration within its range. Orange Accent Seconds Hand — Cockpit-Gauge Legibility: The seconds hand carries an orange accent that makes it immediately trackable against the graduated countdown scale, even in bright sunlight or motion. The orange references the warm analogue gauge colours of classic GT cockpits from the Speedtimer's era of reference — a period colour choice that doubles as a functional legibility tool. Classic Car Dial — Visual Heritage of Motorsport: The dial colour recalls the instrument panel tones of GT racing cars from the 1960s and 70s — muted, warm, and deliberately analogue in character. A dial that looks at home on a wrist trackside or at a concours event. Caliber 6R55 — 72-Hour Power Reserve, 12.0mm Slim: 24 jewels, approximately 72 hours of power reserve, automatic with hand-winding, hacking seconds. The 12.0mm case thickness is notably slim for a sports automatic, making the HBC003J comfortable under a sleeve and wearable in formal contexts without feeling oversized. Curved sapphire crystal with inner AR coating. Dia-Shield scratch resistance. Fine-Pitch Stainless Steel Bracelet — Core Shop Exclusive: The fine-pitch bracelet is described by Seiko as fitting closely to wrist contours, reducing the gap between links for a more integrated, skin-close feel. One-push triple fold clasp. Maximum wrist circumference 205mm — generous range. Available exclusively through Seiko Global Brand Core Shops. Released September 2026. Watch Specifications Specification Details Brand Seiko Prospex Speedtimer Model HBC003J Movement Automatic + Manual Winding (Caliber 6R55) Jewels 24 Power Reserve ~72 hours (fully wound) Accuracy +25 / -15 sec per day Complication Countdown Timer Inner Rotating Ring (4 o'clock crown) Case Material Stainless Steel (Dia-Shield) Crystal Curved Sapphire (Inner Anti-Reflective Coating) Case Size 39.5mm x 44.5mm, 12.0mm thick Weight 154g Lume Lumibrite (Hands & Indices) Caseback Screw Band Material Stainless Steel (Fine-Pitch, One-Push Triple Fold) Max Wrist Size 205mm Water Resistance 200m (20ATM) Anti-Magnetic Yes Distribution Seiko Global Brand Core Shop Exclusive Release Date September 2026 Country of Origin Japan Product File Brand: Seiko Product: Wristwatch Movement: Automatic Display: Analog