Seiko 5 Sports Field Series 41 MM Automatic Nylon SS Brown Earth Dial Watch HDB009K1

The Seiko 5 Sports Field Series is the 2026 update to Seiko's entry-level field watch, in a new 41mm case that sits between the existing 36, 39 and 42mm formats. Its defining feature is a bidirectional rotating compass bezel with a diamond-knurled profile, which is both functional for grip and the visual signature of the series.

This reference has a brown earth-tone dial with LumiBrite on the numerals, hands and bezel, on a double-layer nylon strap with a leather lining and pin buckle. Inside is the Caliber 4R36, one of Seiko's most widely used automatics: robust, hand-windable, with hacking seconds and a day-date display. Its ubiquity is a practical advantage, since any watchmaker can service it inexpensively.

Key facts
Brand: Seiko
Collection: Seiko 5 Sports, Field Series
Reference: HDB009K1
Movement: Caliber 4R36 automatic with manual winding, 24 jewels, 21,600 vph, approx. 41-hour reserve, hacking seconds, day-date
Case material: Stainless steel, brushed
Case size: 41.0 mm diameter, 13.2 mm thick, 48.5 mm lug-to-lug
Dial: Brown earth tone with LumiBrite
Bezel: Bidirectional rotating steel compass bezel, diamond-knurled
Crystal: Curved Hardlex
Strap: Double-layer nylon with leather lining and pin buckle, 20 mm lug width
Water resistance: 10 bar / 100 m

Specifications

Caliber Number: 4R36
Movement Type: Automatic with manual winding
Jewels: 24
Frequency: 21,600 vibrations per hour (3 Hz)
Power reserve: Approx. 41 hours
Functions: Hours, minutes, seconds, day and date
Stop second hand (hacking) function
Case Material: Stainless steel
Thickness: 13.2 mm
Diameter: 41.0 mm
Lug-to-lug: 48.5 mm
Lug width: 20 mm
Bezel: Bidirectional rotating compass bezel
Crystal: Curved Hardlex
LumiBrite on hands, indexes and bezel
Strap: Double-layer nylon with leather lining, pin buckle
Water Resistance: 10 bar (100 m)
See-through and screw caseback

Frequently Asked Questions

Q: Does this watch have a GMT function?
A: No. It is a three-hand watch with day and date. The rotating bezel is a compass scale, not a second time zone.

Q: Is this watch new and authentic?
A: Yes. Every watch we sell is brand new and 100% authentic, backed by our money-back guarantee.

Q: How is it shipped?
A: Worldwide by DHL Express from Dubai, with tracking details provided on every order.

Q: What is the warranty?
A: Seiko international manufacturer warranty, plus our own store support.