This is the VIBRANT All-in-One Travel Mug:
I found it on Amazon earlier this year and since then, it has become one of my most used possessions.
The outside is a sleek, matte material that has great grip and is heat-proof. I have this dark turquoise one, but it also comes in black and burgundy (both are beautiful!). The bottle comes with a tea strainer insert that can be taken apart (for ease of washing and putting tea leaves inside). It is light and easy to carry around.
The inside is stainless steel. I love this because so many insulated water bottles are plastic on the inside, which is not good for my hot liquids. It also successfully keeps my liquids hot (sometimes too hot) all day long (I once went hiking in late fall and my tea was still piercing hot by the end of the day). It is also leak-proof, which is an issue that I have faced with my hot water bottles since I was a kid.
It was a little pricy (about $25) but for all that it does, this is an amazing product that is both extremely functional and aesthetically-pleasing!