It’s a Kalmar 2 made from tungum (a grade of bronze highly resistant to patination) by H2O Watch. You can customize with choices of bezels, crystals, dials, hands, movements, casebacks and bands. Takes an average of 4-6 weeks (sometimes longer) to build and send but totally worth the wait. https://www.h2o-watch.com/h2o-uhren/h2o-kalmar-2-tungum.html