First, it is a nice looking growler an looks like it should hold up to abuse. What I noticed right away was there were instructions on how to open the growler, and doing the steps in reverse how to close the growler. I’ve used many a growler over the years with different types of closures but this is the first one I’ve seen that had instructions. Trust me, you’ll need then. Be sure to practice many a times before having it filled as you will most likely have to close it for whoever filled it up. Part of the issue in closing is you have to force the cap across the clamp to get it back into a closing position, A little design changes could probably have addressed the issue, see if MiiR addresses the issue. I saw one comment of their website from another user that complained about the same thing.
Second issue, it leaks. Not a good thing for a growler you paid $59 for. I filled mine up with warm water, placed the cap back into position and proceeded to shake things up. Doing this I noticed water dripping down around the cap. I figured it could just have been water from me filling it so wiped it down and shook it again. Water again drips out when held upside down. I repeated this several more times with the same results every time. I grabbed my glass growler with a ceramic clamp top and tested it out, no leaks. My glass one cost $12, granted more fragile then the MiiR one but leakage is not a good thing for beer storage.
Right now I coming to tell people to pass on this growler. The lid closing issue isn’t a deal breaker but the leaking is one, pass on this growler until MiiR addresses the issues