I usually use a smaller size, and I haven't used the 500ml ones very often, so they've been stored for a long time. One is a Thermos, and the other is a Topvalu, I think? I'm not sure because they were gifts. Both are in good working order. They have been cleaned, but there are scratches on the bottom, etc., and they are not as light, small, or dishwasher-safe as more recent models. Please be aware of this. I think they can be used for ice, outdoor activities, in the car, or for pet water, etc.