“I bought this because I saw tennis players using it, so I figured it must keep drinks cool for a long time. But it doesn't keep drinks long at all, maybe two hours. I filled it up to the top with ice, but the water was warm within a few hours. The bottle that I usually use is a Contigo. When I use the Contigo water and ice that I filled on one day is still ice cold the next day, probably 16 to 18 hours. I just wish I had bought this Waterdrop on Amazon so I could return it! It does not work at all for its intended purpose.”
