My brother bought me a water bottle from Rocky Mountains National Park. I'm am wondering because of health concerns if it is aluminium or stainless steel. How do I tell? A magnet stuck to it... I also have a food thermos and I'm wondering if that is stainless steel or aluminium. A magnet did not stick to it and I got if a few years ago in target. It is from the Thermos company. Thanks!!!

personalized stainless steel water bottles