As someone who has 3 Klean Kanteen bottles (2 thin walled, 1 insulated), I came across these Hydro Flasks at an outdoor trade show, and struck up a conversation with the supplier along the lines of "What makes these better than KK?" 

Well after a 5 minute chat I was given an orange coloured 21oz flask to try. At first, I was wary of something that I presumed was a pretender to the crown, but after a couple of days of avoidance I decided it was time to give it a proper go. 

For keeping drinks hot and cold there isn't much difference to many other drinks flasks, it does what it says in the blurb, but where it surpasses its KK rival for me is on the outside.

It has a coloured powder coating that has a slightly textured feel, and gives it a matt colouring. Now this coating makes the grip much easier, and a lot less slippy than a smooth shiny bottle, and it's tough, I know because I've treated it quite abysmally, from chucking it into my gym bag to bashing it about in the back of 4x4s.

Apart from the time that it dropped 5 feet onto rocks and I chipped a tiny corner, the coating has lasted so much better than many other 'prettier' shiny bottles. The matt coating is also great when you hang it on the outside of your rucksack, as you wont blind your friends with the sun glinting off a shiny coating.

Mainly because of the fact that I don't mind treating it roughly (and that's really its job), it has now beaten it's rival into first place, and has become my drinks flask of choice, oh, and did I mention at 21oz it holds one more ounce that the Klean Kanteen. Result!

Technical Stuff

• Sizes: 12, 18, 21 & 24oz
• Colours: various colours available (dependent on size).      New colours released each year.
• TempShieldTM insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hours
• Durable 18/8 Pro-Grade Stainless Steel construction
• BPA-Free and Phthalate-Free
• Compatible with Standard Mouth Insulated Sport Cap
• Lifetime Warranty

Dimensions of the 21 oz

• Volume - 621 mL
• Mouth Diameter - 1.91"
• Diameter - 2.87"
• Height - 9.4"
• Weight - 11.3 oz

Website: www.hydroflask.com/en