Decided to buy the 500ml bottle as I really struggle to drink water so thought that if I had it in a bottle that stayed cold for up to 24 hours then it was worth trying. The finish on the bottle is really good and cleaning is very simple. I read a review of someone saying that there was an awful smell coming from the bottle when they were using it which I haven't found thank god. I've washed the bottle every day so maybe it is down to how it is washed. A bit of Fairy Liquid with hot water inside and shaken and then rinsed. A great purchase even though it is probably a little expensive to other flasks on the market.