I bought this for my wife so that she can take hot water for tea with her to work. It keeps the water hot fine, but my wife used it once and won't use it again. The reason: the bottle cap is far too hard to close, and even harder to open because the cap is attached to a strap that is designed to keep you from losing the cap. That strap material keeps the cap from turning freely, and the friction from that strap makes it very hard to close or open the cap. We are also old, so I can see how it would become even harder to open/close as arthritis sets in even more. Obviously, nobody bothered to do any usability testing with this. It needs improvement.

Holds cool water (from fridge dispenser) cool for entire work day! In particular, the lid is quite secure and appears to also be insulated.