Comments:
The movement
It's a very nice watch and still in my collection.
I might be a teensy bit partial here. This is the COS “ZM” variant, which counts minutes on the central axis. With this in mind, the Massena piece is certainly my favorite version with subdials.
Habring 2 20 Time Zone Chronograph. An original way to operate the chronograph through the crown.
Here are two photos I found on the net,
This one to be credited to Watchley Dot Com.
One official:
This one to be credited to Watchley Dot Com.
Super dial and case, and I never saw a chrono like that.
I think our dear Brandon can explain us how it works, it is quite fascinating.
Best,
Nicolas
Display -> Operate
This message has been edited by cazalea on 2023-02-02 18:46:26
Here are a few pictures I took of the one I own...
The movement
It's a very nice watch and still in my collection.
I can concur Love mine although have not worn it for a while Massena and the Habrings hit this one out of the park
True my friend. Those shots are probably 7 to 8 years old now.
I have too many pictures of watches to take 
I heard someone needed my help🦸🏼♂️
An explanation of the how the chronograph works:
Richard’s patented COS mechanism does away with pushers and lets the user control the chronograph entirely through the crown. When the crown is up against the case, turning the crown counter clockwise will activate the chronograph. Once running, turning the crown clockwise will in turn stop the chronograph. Turning the crown clockwise again, with a little more effort will reset the chronograph. Pulling out the crown one position allows for you to wind the watch, and the last position to set the time.
I really love this version of the COS which I had in my hands and foolishly passed on🤦♂️ once upon a time. William and the Habrings completely nailed it with this piece and I’d place it as my 2nd favorite version of the COS ever made!😉😉 B
Richard’s patented COS mechanism does away with pushers and lets the user control the chronograph entirely through the crown. When the crown is up against the case, turning the crown counter clockwise will activate the chronograph. Once running, turning the crown clockwise will in turn stop the chronograph. Turning the crown clockwise again, with a little more effort will reset the chronograph. Pulling out the crown one position allows for you to wind the watch, and the last position to set the time.
I really love this version of the COS which I had in my hands and foolishly passed on🤦♂️ once upon a time. William and the Habrings completely nailed it with this piece and I’d place it as my 2nd favorite version of the COS ever made!😉😉 B
Thank you so much for your detailed explanations, my friend. Now you said this is your second favorite version of the COS. Which is your favorite, then?
Le Boom!
I might be a teensy bit partial here. This is the COS “ZM” variant, which counts minutes on the central axis. With this in mind, the Massena piece is certainly my favorite version with subdials.
It's a really cool way of executing a chronograph
The lack of pushers creates a cleaner look that I like
I love this one; and this execution of the dial too.
My only issue, 42mm case.
Lots of like in Habring. I will buy another at some point.
"Displayed" through the crown???
Not a bad watch, but nothing revolutionary- it works like a monopusher. As everyone knows PP had already that kind of "complication" in the 1940's.
It would be a bit more of a feat if the chronograph had a chronograph hour counter that also would have to be set to zero or, even better, a flyback mechanism.
How to do a flyback without pushers and only activated by the crown...
Not like monopusher ....
... since with a monopusher you cannot add time measurements. After stopping, always a rest will follow. With the COS, you always can add the measurements by restarting the chrono without resetting it.
Marcus
Marcus