Digging through some accumulation and found this Sinn watch box. I had a couple of Sinn chronographs years ago but don’t remember if this was for one of those. I have no idea what watch it goes to. Any ideas?

Thanks.

There is a Sinn U1 black on goodwill website. Looks legit. I don’t have a link but easy search there.

I got a Sinn 556 i in Frankfurt about a year ago as a first automatic watch, and have worn it infrequently since buying it. The main reason being that I seem to need to ‘fight’ for it to keep power through the night, and that often means wearing it at least 12 hours that day and putting it back on immediately upon waking. I don’t think I’ve ever had it keep power for more than 4 days in a row, even with daily wear.

In theory I live autos, and in practice I really want to love them too, so…

Sinn 556 i dies after ~10 hours off wrist, is this normal?

I’ve seen a few posts where people state that the external AR coating has a hardness of 1800 vickers yet I can find no mention of this on the Sinn website.

Can anyone confirm this claim?