I took a chance and purchased these for the Grand Opening of my brewery. I ordered these late and they arrived the morning of the opening. We put them on the sample bottles and opened the door not knowing what would happen. They fit on liquor bottles as well as our Boston Round Growlers. They look sleek and expensive and worked really great! It's a nice smooth pour that doesn't really require the stop mechanism that other brands offer. Very easy to use and a snug fit. Would definitely buy them again.