SUO SUO Cool Ring 28°ICE M size (Inner diameter 32cm) Gray Purchased new last summer and used about once every few days. There is a slight feeling of use, but there are no other issues such as liquid leakage. I am a woman of average build, and the M size was just the right size for me. Will be shipped in a waterproof box for Yu-Packet Post. If you have any questions, please feel free to ask.