# Regarding Jaeger-LeCoultre Case and Catalog Numbers



## SFoskett

I've been exploring the Jaeger-LeCoultre product lineup (now that I'm a customer) and thought I should try to clear up one issue that confused me quite a bit. I've also noticed this question comes up repeatedly in this and other forums, so let me be clear:

Each Jaeger-LeCoultre timepiece has two similar but different model numbers!

The "Catalog Number" is what's shown on the web site and in other public materials
The "Case Number" is what is actually engraved on the back of your watch

These numbers are confusingly similar, leading many buyers to be concerned that they got a different model than they paid for, that theirs is an outdated model, or that theirs is a fake since the numbers don't match. That's the bad part.

The good part is that Jaeger-LeCoultre has been pretty good about using consistent numbering and encoding useful information in these numbers, if only you know where to look!

Here's the decoder:


Jaeger-LeCoultre catalog numbers are in three parts, "xxx-cs-dd"
"xxx" is the watch case model from the catalog (note that this is usually different from the similar number engraved on the case!)
"c" tells you what material the case is made from (using the same code as the case number)
"s" tells you about the bracelet or strap and buckle
"dd" probably encodes the dial and crystal configuration, but it's not very consistent or clear

Jaeger-LeCoultre case numbers are also in three parts, "xxx-c-mm"
"xxx" is the internal watch case number (different from the catalog case number)
"c" is the case material code
"mm" is the movement or calibre code


This is all extremely confusing but marvelously helpful. For example, every Jaeger-LeCoultre watch with "8" as fourth digit has a stainless steel case, and if your Reverso has a "54" as the final number on the case (like mine!), it's using their Calibre 854.

I put together a wiki page to document the many and various case numbers, and I've been populating it with the current catalog. But it's got a long way to go. I welcome your suggestions!
Jaeger-LeCoultre models - Watch Wiki, The Best Watches And Watch Brands

And I hope this helps alleviate some of the confusion and genuine concern people have regarding the mismatch between their watch's catalog number and the number engraved on the back of the case.


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## 3leggedpony

aagh, I wish I'd seen this earlier before shipping my new watch back to the AD!


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## SFoskett

I wonder just how many watches get shipped back to the dealer after the buyer discovers that the number engraved on the back doesn't match what they saw in the catalog or website! You are certainly not alone with this confusion, and I am confused why the company would use two different sets of numbers when they could easily reconcile them in the space of just one year or so.


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## PP101

I have just come across this thread and the Wiki, for which many thanks. This is very helpful.

However, the Wiki has failed to answer one question which has been bugging me: the difference between the Duo (271) and the Duo Night & Day (272). I am looking to buy a pink gold in the pre-owned market and simply cannot get to the bottom of the difference.

Interestingly the JLC Salon in London is as confused as everyone else by the numbering: they told me that strap code 4 was one colour and 5 another, whereas the Wiki makes clear that one is pin buckle and one is deployant which makes more sense given what I saw in the Salon !


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