I bought two of these mugs for use in my occupation (air carrier pilot). The mug goes in with my headset/iPad in my flight bag and I *really* needed something that would not leak during dead heads (flying in the passenger compartment to reposition to a different airport where you are needed) where it can easily be flipped on its side in an overhead compartment, etc for an extended period. Does this in spades. And the coffee does remain hot for hours. As my spouse can surprisedly attest to as seen in the text pic below.

I see a previous gentleman having issues with the lid reassembly. I attached Stanley's own video for the reassembly. It IS that simple (once you know the sequence). :)

This is the best travel mug I have ever owned. The construction is excellent and it feels like it will last a very long time. My favorite part about this mug is the lid. It disassembles into two pieces for cleaning. This allows every part of the lid to be cleaned thoroughly and easily. I always worry about cleaning other kids fully with the small books that are impossible to reach, but this lid is designed perfectly. I highly recommend unless you are looking for a mug with a lid that can be opened with one hand as this requires both.

I am very picky about travel mugs and this one checked all of the boxes. I wanted a mug that fit well in any cup holder, didn’t leak, had a simple mechanism for opening and closing, and had a nice outflow of my coffee. This thing is perfect. I’ve had many versions of Stanley’s throughout my coffee drinking years and this one by far takes the cake.
PS. The reviews you may see about the lid being complicated to assemble is ridiculous. If you can put gas in your car you can put this lid together.

We literally used this once. I took apart the lid for cleaning and when putting it back together, the plastic prongs on the green part of the lid didn’t fit into the threads as designed and they both are now warped and look like they may break. Regardless, it is unusable. I did not use excessive force, they simple gave expected resistance when turning a lock proof lid. Soft plastic.