I was emailing back and forth with the creator of the Ziss tumbler. I was trying to get a group buy going on here. It did not happen in time. The creator emailed me a couple weeks later to notify me that he no longer ships to the US because he signed a contract with someone for US sales of the Ziss. Maybe it was "cobalt" who bound him? I do own a Ziss, and the cobalt looks IDENTICAL. The design was patent, so I don't seeing this being cobalts but instead ziss just reboxed and sold by cobalt. They are even the same size. Ziss sold them as 65 mm and 80 mm. I bought the 80 mm and love it. Cobalt advertises the same size as well.