Seiko unveils new HDB004 and HDB005 stainless-steel automatics with 4R36 movements

Seiko has added two new references to the 5 Sports SKX series, the HDB004 and HDB005. They're both now listed on the company's US website, tagged as October 2026 releases. They don't have a price tag, however. Also, neither is a limited edition, which makes them the exceptions in that list of new SKX watches alongside them on that page.

The HDB005 features a green dial with a matching green bezel insert. It has rose gold-toned hands and markers. The HDB004 does a complete 180 in terms of design — it sports a silver-white sunburst dial inside a black bezel, with yellow gold-toned hands and applied indexes. Both come on a steel bracelet and the day-date aperture at 3 o'clock, below the Seiko 5 logo.

Mechanically, these two are the same watch. Seiko's spec panel lists the 4R36 automatic on both, with 24 jewels, manual winding, a stop-seconds function and roughly 41 hours of reserve. The stainless-steel case measures 42.5 mm across and is 14.2 mm thick, with a 46 mm lug-to-lug span, 22 mm lug width and a 169 g weight on the bracelet. Water resistance is 10 bar and magnetic resistance 4,800 A/m. LumiBrite covers the hands and indexes.

The crystal is curved Hardlex and not sapphire, which has now become quite common across the 5 Sports line. Elsewhere, you get a unidirectional rotating bezel, a see-through screw case back, and a three-fold clasp with push-button release (and a secure lock).

That leaves price as the main question. Seiko has given us no figure for either reference. The 145th-anniversary HDB003, which shares this case and the same October window, is listed at $450. 

Full retail references fo are HDB004K1 and HDB005K1; the K1 suffixes are going to the international versions.