Excellent quality.
It withstands the test of time.
As for the negatives: the change in the color of the rubber inside from food and its lack of waterproofing in case of transporting food with some moisture (oily and soupy foods).

I put boiling water and after two and a half hours it was cold!
The rubber doesn't hold the liquids, if the container is turned upside down, it leaks fluids.
Luckily, I tested it with water and returned it.

Unacceptable product. I have purchased two and although they seem to secure well, obviously the rubber does not seal, resulting in slightly more liquid foods spilling out.

I bought it for all-day elementary school use.. not even close. It doesn't keep the food warm, the liquids from the food spill out, and one clip broke quickly. I expected something better from this company, it's a shame for the money, I even bought 2.

It doesn't run for now (I've had it for a month with weekly use) but it is definitely not warm! I bought it to keep the food warm but it doesn't even do that! The lid is thin plastic that doesn't retain any heat. I need something else for school lunches...