The storyWhy this reference matters
The 103 is the oldest model still alive at Sinn: a pilot's chronograph with a bezel, a screw-down crown and the air of a cockpit. In 2013 the brand introduced the 104, which is the same argument with three hands and a simple movement. Sinn calls it die klassische Fliegeruhr, the classic aviator's watch, and it shares its brutally edged case with the EZM 3 diver. Fratello, reviewing it ten years on, summed up why it works: it is simple, it is solid and it is well made.
There is none of the house's technical paraphernalia here. No Tegiment hardening, no copper capsule, no oil filling. What there is is sapphire in front, slightly domed and anti-reflective on both faces, and sapphire behind, a screw-down crown with guards, 200 metres of water resistance and low-pressure resistance, which on a watch built for flying makes perfect sense.
The engine changed supplier without changing the spec sheet. The first 104s used an ETA 2836-2. Today they run the equivalent Sellita SW220-1, with day and date, 28,800 vibrations per hour and around 41 hours of reserve. That is exactly the kind of decision that explains why the 104 has become so many people's default watch: it promises nothing strange and delivers everything it promises.
SpecificationsThe numbers, in one table
| Brand | Sinn |
|---|---|
| Family | 104 |
| Reference | 104 St Sa A |
| Years made | desde 2015 |
| Calibre | Sellita SW220-1 (unidades anteriores: ETA 2836-2) |
| Movement | Automatico |
| Frequency | 28.800 alt/h (4 Hz) |
| Power reserve | Unas 41 horas |
| Complications | Día · Fecha · Bisel giratorio bidireccional de cuenta atrás de 60 minutos |
| Diameter | 41 mm |
| Thickness | 11.9 mm |
| Lug to lug | 47 mm |
| Lug width | 20 mm |
| Case | Acero inoxidable pulido |
| Crystal | Cristal de zafiro ligeramente abombado con antirreflejos por las dos caras; fondo de zafiro con antirreflejos interior |
| Water resistance | 20 bar (200 m), además resistente a la baja presión |
IdentificationHow to tell it apart
The final letter is the key. At Sinn, St means a steel case and Sa a sapphire crystal, and the A that follows means an Arabic-numeral dial. The 104 St Sa I is the same watch with bar markers, and from that come the white-dial I W of 2017 and the blue I B and anthracite I A, both from 2019. So a 104 with numerals on the dial is always an A.
Day and date sit together at three, with a bilingual German and English day wheel and a thin white rectangle framing the two windows. That frame is the 104's signature and does not appear on the 103. The dial is matt black, with big rectangular hour markers and a minute track in two sizes, and the hands are the syringe type.
The bezel is the most recognisable part: bidirectional, aluminium insert, a 60-minute scale numbered anticlockwise to count down, 60 clicks. It is a captive bezel, held by the tiny screws you can see around the edge. Measurements: 41 mm across, 47 lug to lug, 11.9 tall and 20 mm between the lugs, with drilled lugs.
CollectingWhat collectors check
The case leaves the factory polished all over, and on a watch of this character it marks straight away. So much so that the US distributor once commissioned a run with a matt bead-blasted case precisely because customers were asking for it. If you want a 104 to actually use, accept that it will scratch. If you want a pristine one, look at the edges of the lugs, where wear shows first.
Try the bezel before anything else. The clicks should be dry and there should be no lateral play. It is a captive bezel, and once it starts to wobble the repair means taking it apart. On the H-link bracelet, Fratello noted some side play even from new despite the hex screws. That is not a fault in your example, it is how the thing is.
Drilled lugs make strap changes easy, and they also tell tales: if the holes are marked or slightly oval, that watch has changed straps many times. Finally, look through the sapphire back to date it. If the calibre on show is an ETA 2836-2, you have an early example. The Sellita SW220-1 belongs to later production.
Common questionsWhat people ask us about this reference
What does 104 St Sa A mean in Sinn's naming?
St is a steel case, Sa a sapphire crystal, and A an Arabic-numeral dial. The version with bar markers is called the 104 St Sa I.
What is the bezel on the Sinn 104 for?
It is a 60-minute countdown, numbered anticlockwise so you read the time remaining rather than the time elapsed. It turns both ways with 60 clicks and has an aluminium insert.
Which movement does the Sinn 104 use?
A Sellita SW220-1 automatic with day and date, running at 28,800 vibrations per hour with about 41 hours of reserve. The early years used the equivalent ETA 2836-2.
How big is the Sinn 104?
41 mm across, 47 mm lug to lug, 11.9 mm tall and 20 mm between the lugs, rated to 200 metres.
Keep readingWhere to go from here
Close relativesThe ones it gets confused with
See Sinn 104 at auction now → What is up for sale on Catawiki today. Read the page above before you bid: half the mistakes come from not checking the reference.Confidence: media — this page was checked against the sources below. If a detail looks wrong to you, write to us and we will fix it.