When this tumbler first arrived, I was a bit surprised at how small it was. With the double-walled design, intended to keep your tea hot as long as possible, the interior volume is quite smaller than it appears. After several weeks of use, I have determined that there are three primary ways in which this tumbler can be utilized.
First, the strainer can be removed from the mouth of the container, the tea bag or leaves put inside, water poured into the tumbler, and the strainer replaced. This allows tea to be steeped indefinitely, and tea to be sipped while the leaves are still inside the tumbler. This works well if you are drinking a tea that is unaffected by long or indefinite steep times.
Second, the tumbler can be used as an on-the-go container for prepared tea. Simply remove the strainer and leave it at home, and the tumbler could be used for keeping tea, prepared in a pot or other vessel, hot on the way to another location.
Third, in the case of a lack of another brewing vessel, this tumbler can serve for that job too. Remove the strainer, put in the tea, put in the hot water, replace the strainer, wait for steeping to finish, and then simply pour from the tumbler into cups for serving.
My experience with these three methods was varied. With the first method, I found that, because the leaves or bag float loose inside the container and are not held back from the strainer, they would often float forward with the steeped tea and block/clog the strainer while I tried to drink. The second method worked out fairly well. My only complaint was that it seemed as though the tea still cooled off a bit fast, despite the double-walled design. But the double-walls did insulate one’s hand from the heat of the contents. In the third case, this worked only slightly better than the first method, running into the same issues, yet being a little more controlled for pouring, as I was attempting to pour into a mug that I could see rather than my mouth.
Overall, while I appreciate the design of this tumbler, I am not sure that the functionality is quite at the best point yet to make it worth a purchase. For overall usability, I would rate it a 6.5/10.