Seiko SBSA281: specifications and what to check

4R36 shows a day; 4R34 does not

Two calibres run through the 5 Sports references documented here, and the difference is visible on the dial.

• 4R34 — 24-hour hand, stop seconds, date
• 4R36 — stop seconds, day and date

Both are 24 jewels, both are approximately 41 hours, both are automatic with manual winding, and neither has a published daily accuracy figure.

So the complications are the whole distinction, and they are easy to get wrong in a listing written from the collection name rather than the reference.

Set both displays while you have the watch. Advance the date past midnight and watch it change; then set the day and confirm it indexes cleanly into its window. The day wheel is the component most often damaged, usually by an owner setting the date during the hours when the change mechanism is engaged, and a day that sticks half-way is a repair rather than a quirk.

Nylon is the cheapest thing on the watch

The band is nylon, 225.0 mm long, on 22 mm lugs.

It is also, by a distance, the component most likely to look tired — and the one a seller is least likely to mention, because fabric wear reads as character rather than damage.

Check three places.

The spring bar holes, or the folded-through section if there are none. Fraying starts where the fabric is pierced or doubled.

The keeper, the loop that holds the tail. Nylon keepers stretch, and a stretched keeper lets the strap flap.

The buckle holes, where the tongue has worn the weave open.

None of that is expensive to put right — a nylon strap is a commodity — but a buyer opening a box to a grubby, frayed strap on a limited edition has a legitimate complaint. Either replace it, or photograph it honestly and price it in. Say which one you did.

A numbered collaboration is bought for the whole package

The case back is see-through and screwed, engraved LIMITED EDITION with a serial number, from an edition of 2,000 pieces.

Collaboration editions attract buyers who care about the collaboration, and those buyers want everything that came in the box — the specific packaging, the documentation, and any additional material the edition shipped with.

So at the buy: establish exactly what exists, photograph all of it, and record the serial number. At the sale: quote the number and list the contents.

A loose watch from a numbered edition is a different product from a complete one, and pretending otherwise is the fastest way to a dispute with the most informed kind of buyer.

Case, crystal and bezel

42.5 mm across, 13.4 mm thick, 46.0 mm lug to lug, 95.0 g, rated 10 bar, magnetic resistance 4,800 A/m.

Ninety-five grams is light for a 42.5 mm steel watch, and the nylon strap is most of the reason. Fit a bracelet and that changes.

The crystal is curved Hardlex — Seiko's hardened mineral glass, which scratches where sapphire would not and can often be polished. Grade it on that basis and describe it by name rather than calling it sapphire.

The bezel is unidirectional rotating, which differs from the two-way 24-hour bezel on the GMT reference in the same series. Try clockwise first: it should not move.

LumiBrite is on the hands and indexes only. Do not expect the bezel to glow, and do not flag its absence as a fault.