I just love this mug. There is nothing any better than a cold drink in a frozen mug. I spend a lot of time outdoors and on my patio in the spring and summer. I use this mug all the time!
The design is really ingenious. What you have is a mug that holds a 12 ounce beer, soda or what have you. The mug actually has two layers with a non-toxic liquid inbetween the two layers. What you do is place the mug in your freezer upside down (because of the expansion of the liquid when it freezes). You let it freeze completely. It usually takes about 6-8 hours. You can then take it out of the freezer and pour in your beverage.
I love the mug because you have a drink that is in a frosty mug. Nothing is more refreshing. Also, because of the frozen liquid, it stays frozen and cold longer. I love the fact that there is no ice needed and therefore no watered down beverages.
I have a couple of these in my freezer at all times. I wouldn't hesitate to buy this product again!