1 / 6 Front
Condition: Very Good
How we grade- New
- Unworn
- Excellent
- Very Good
- Good
- Refurbished
Very Good: Worn and cared for. Light scratches you can see at arm’s length on the case or bracelet. Crystal and dial clean.
Honest wear on the case and bracelet. Dial and crystal are clean.
Tap a flaw to see it on the photo. Positions are given like a clock face, looking at the dial.
Condition report
Inspected Oct 29 · every part checked one by one
| Part | Condition | Notes |
|---|---|---|
| Case and lugs | Visible wear | 1 Small ding on the lug at 5 o’clock |
| Bezel | Light wear | 2 Scuff on the bezel edge at 2 o’clock |
| Crystal | No marks | — |
| Dial | No marks | — |
| Hands | No marks | — |
| Crown | No marks | — |
| Bracelet and clasp | Visible wear | 3 Hairlines across the bracelet; slight stretch |
| Caseback | Light wear | — |
Function checks
- Runs and keeps time
- Time setting, hands aligned
- Bezel turns and clicks cleanly
- Lume charges and glows
- Winds and hacks
- Water resistance pressure test Not tested by us. Treat as splash-proof until a watchmaker tests it.
Not serviced by us. Healthy amplitude for an NH35.
Timing on a timegrapher
| Position | Rate | Amplitude | Beat error |
|---|---|---|---|
| Dial up | +9 s/day | 274° | 0.5 ms |
| Crown down | +17 s/day | 247° | 0.6 ms |
Healthy. Strong amplitude and keeps time well inside the maker’s spec. Maker’s spec: −20 to +40 s/day.
What these numbers mean
- Rate
- Seconds gained (+) or lost (−) per day. Affordable automatics are specced around −20 to +40; most run far better.
- Amplitude
- How far the balance wheel swings. A healthy, fully wound movement reads roughly 250–315° dial up; it drops in vertical positions, and low readings mean it’s due a service.
- Beat error
- How evenly the balance ticks and tocks, in milliseconds. Under about 0.6 ms is good.
Will it fit?
41 mm case · 48 mm lug to lug · 12.8 mm thick
Fits well.
Estimate: the flat top of a wrist is about 29% of its circumference. How we work this out.
Specifications
- Brand
- Ostrova
- Model
- Abyss 300
- Reference
- OS-4121
- Case diameter
- 41 mm
- Lug to lug
- 48 mm
- Thickness
- 12.8 mm
- Lug width
- 20 mm
- Case material
- Stainless steel
- Crystal
- Sapphire
- Water resistance
- 200 m
- Movement
- Automatic, Seiko NH35A
- Accuracy (maker’s spec)
- −20 to +40 s/day
- Power reserve
- 41 h
- Beat rate
- 21,600 bph
- Dial
- Blue
- Strap
- Steel three-link bracelet
- Year
- Circa 2021
- Condition
- Very Good (pre-owned)
- Listed
- Oct 29, 2026
In the box
- Original boxIncluded
- Warranty card / papersNot included
- ManualNot included
- Extra bracelet links ×1Included
- Spare strapNot included
- Numbered security tagIncluded
About this watch
The sunburst blue version of the Abyss: it flashes from navy to bright blue as the light moves. Worn but cared for, and priced to reflect it.
Shipping, returns and questions
Shipping
$12 insured shipping, free over $250. Ships in 1–2 business days, tracked, signature on orders over $300. US only for now.
Returns
14 days from delivery. Unworn since it arrived, with the numbered tag still attached. Refunded to your original payment once it’s back and checked.
Why the serial is hidden
We record every serial privately before listing. Hiding it in photos stops it being copied onto fake paperwork, and lets us confirm a returned watch is the one we sent.
Is it authentic?
We inspect every watch, inside and out where the caseback allows, before it’s listed, and we never sell replicas. If a watch ever turns out not to be what we described, you get a full refund including shipping.
Does it come with a warranty?
Pre-owned watches don’t carry the maker’s warranty, and we don’t add our own yet. That’s why we time mechanical watches and show you the numbers, and why there’s a 14-day return window.
Can you size the bracelet?
Tell us your wrist size after checkout and we’ll remove links before shipping, at no charge, and send the spare links with the watch.
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