I’m shocked! SHOCKED, I tell you!
Weird. That’s a “shop hard” IP67 caliper but no in/mm button.
That’s basically my all time favorite digital caliper. I got mine many years ago from Enco for ~$120 or so on sale.
Yours looks like someone was very hard on it as mine doesn’t look anywhere near that bad after probably 10 years of use.
I got the 6” caliper from Harbor Freight many years ago and it works great: 6 In. Digital Caliper
I got it on sale, but even at $20 it’s a good deal. It may not be of the highest quality, but seems very accurate for my needs.