Horological Atlas
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slow· DressReference model

O 11

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No longer in the collectionper the house, October 2026
Last list price
USD300

A black steel case with a black dial and an anthracite hand, worn on a brown Italian calf leather strap. The O is the largest of the quartz slows at 42.5 mm wide and 43 mm long, with softly rounded edges, 11.45 mm of height under a K1 mineral glass and 100 m of water resistance. A Ronda 505.24 Swiss Made quartz moves its only hand once around a 24-hour dial each day. Read at a glance, the house says, it is good to a minute or two. 65 g without the box.

Movement
Ronda 505.24 Swiss Made, quartz
Case
42.5 mmStainless steel
Battery
45 mo
Water
100 m

Specifications

Case
Construction
Black steel case, 42.5 mm wide and 43 mm long, 11.45 mm thick with its glass (9.8 mm without), extra hardened K1 mineral glass with a 34 mm opening
Diameter
42.5 mm
Material
Stainless steel
Lug width
22 mm
Lug to lug
43 mm
Water resistance
100 m
Movement
Caliber
Ronda 505.24 Swiss Made, quartz
Battery life
45 months
Jewels
1
Dial & strap
Dial
Black
Hands
Single hand, anthracite
Strap / bracelet
Brown Italian calf leather strap, 22 mm, black stainless steel buckle
Catalogue
Tier
Accessible

Also runs on the Ronda 505.24

56 watches in the catalogue run on it, priced from $270 to $320.

  1. slow
    O 05
    $290
  2. slow
    O 06
    $300
  3. slow
    O 07
    $300
  4. slow
    O 08
    $300
  5. slow
    O 09
    $300
  6. slow
    O 10
    $300
  7. slow
    O 11THIS WATCH
    $300
  8. slow
    O 12
    $300
  9. slow
    O 13
    $300
  10. slow
    O 14
    $300
  11. slow
    O 15
    $300
  12. slow
    Jo 01
    $320

Collector photographs

Taken by people who own this reference: their light, their wear, their patina. Not the maker’s photography. Where the maker hasn’t given us a photograph, one of these is shown as the main image above, always credited. A few are the Atlas’s own, and say so.

No collector photographs yet

If this watch is in your collection, yours would be the first. A photograph on the wrist shows what a studio image cannot: scale, wear, and how the piece has actually aged.

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How to get one

This exact reference

The maker's page for this exact reference, the same page this catalogue's specifications are sourced from.

Direct from slow

slow publishes its current collection and its retailer or service network on its own site. Start there for what is actually in production; this catalogue records references whether or not they are still sold.

Buyer’s tip

Check the model name, case material and any edition number against the maker's own page before buying anywhere else. No reference number is recorded for this watch, so those are the details that identify it.

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