I bought two of these beauties; black and teal/aqua mainly because my husband and I needed a special double walled bottle for the Florida sun and the Dubai heat. THIS BOTTLE REALLY WORKS! It keeps water cold-we added cold water and ice to the black one and left it indirect sun for 5 hours opening it and taking sips. Then, we left it outside over night just to see. The next morning the water inside was still refreshingly cold as we took a sip. And no water condensation outside, which is a huge plus!! Not only does it keep drinks cold but the design is so ascetically pleasing, durable, and easy to carry or place in a bag or purse. I highly recommend this product and would recommend as a great all around bottle!