Klean Kanteen Insulated TK Wide – Red 355ml 5 "Best Insulated Flask" Mrs Drugan 22 July 2019 Over the years I have tried various insulated flasks and they have either leaked, not kept things particularly cold/warm, or both. For me, this product is a game-changer. I’ve just come back from 3 days camping at a fairly rustic campsite. This flask kept ice frozen and my water lovely and cold for 2.5 of those days and this included opening the flask and re-filling with non-cooled water. It was absolute bliss for me as I love ice cold water to drink. It hasn’t leaked once and it’s easy to drink out of. I’ll be taking this in to work with me now. Recommend without hesitation.