I have had my Aladdin tea infuser mug for at least four years and I still love it. It is a double walled plastic thermos mug with and internal fine mesh basket in the lid that sits above the water line until you lower it. You fill the basket with your tea, fill the thermos to the fill line with hot water and when you are ready to lower the basket in the water or raise it, you use the lever on the outside of the lid to move the basket. You never have to open the mug to steep your tea. I read that it is microwave safe, but I have never put mine in the microwave. The lever mechanism has metal, so it would I’d microwave only the mug part.
I first bought one for my sister as a gift and a few months later purchased my own. When comparing notes with her, she complained that the infuser basket on hers would always fall down into the water. Mine clicks when put up and stays in place. I called the company to inquire about the difference and they offered to send a replacement! The new one was just like mine with a clicking sound when the basket is raised. I have read other reviews complaining about the falling basket and I’m guessing Aladdin was paying attention to it and fixed the issue in later models.
My experience with this mug has been fantastic. I do try to keep it upright and and not just toss it in a bag and I haven’t had any leaks. The inside of the mug has etched a little over years of use and slightly discolored, but it doesn’t seem to hold onto smell much. Pouring boiling water and baking soda resolves both those issues. The basket mesh is fine enough that I haven’t had any issues of smaller particles finding their way into my tea. My only complaint is that the basket is small for teas that need lots of room for expansion, but it would make the whole mug bulkier so it’s a trade off I can live with. With the double walled design, the mug keeps tea warm for a while. I find it irritating when I want to drink my tea sooner than later, but it’s better than the opposite problem and my tea is still warm if I forget it for a while.
Someone asked me how well it holds heat so I did an experiment. I poured boiling water in the mug and took the temperature every half hour. It was sitting inside my house (kept at 70F) and I opened the part of the lid that you sip through to stick the thermometer in, then closed it again when I got a temp. Here is what I got: @0m/188F, 30m/149F, 60m/130F, 90m/120F, 120m/109F, 150m/98F It won’t keep your tea warm all day, but it will be warm for a couple hours.
Overall I’m quite satisfied with this mug and I would happily buy it again if it eventually gave out.