3L/5L Pump Action Air Pot Flask with Vacuum Insulated, Safety Lock & Carry Handle for Drink, Tea & Coffee by Crystals® (3L Air Pot Flask)

Product Information

The best of the best are made from 18/8-grade steel (aka 304-grade), whose high nickel content makes it rust-proof and extremely durable. And if you’re heading out there with a friend, even better, because there’s a second plastic ‘buddy cup’ hidden inside the larger metal one. There’s even a built-in tea filter, so you can make tea using loose tea leaves or whatever you find on your adventures. Multi-wall insulation: Double-wall insulation creates a vacuumed layer, which is vital for keeping hot drinks hot and cold drinks cold.

This vacuum-insulated flask from Black+Blum is a highly distinctive and eco-friendly option for keeping your food nice and warm.If you want to slip in into a pocket or take it in backpack, you'll want to pay attention to the shape. The leaflet that comes with the flask doesn’t make any specific claims about how long it keeps drinks hot. The insulation claims to keep water cold for 32 hours, which turned out to be underselling its capability. This Swedish-designed double-walled flask promotes itself as crucial kit for the rugged adventurer, so you whilst you might feel it’s a bit much for a Sunday afternoon stroll in the countryside, you can be assured it won't let you down, no matter the activity.

At 360ml, it holds a decent-sized mugful and promises to keep drinks hot for four hours or cold for eight.We tested flasks that could hold enough for several people (or someone wanting several cups during the day), as well as some that were designed to serve one. Thoughtful details include a twist-and-pour stopper that lets you pour drinks without removing it, and a space-saving handle. Not having to remove the full cap reduces the amount of heat that escapes when using it, so liquids stay hot for longer. For instance, the cup is insulated with plastic, so our tea retained its heat without being too hot to hold. However, the efficiency of this insulated flask and its brushed stainless steel styling makes it one of our favourites.

Key specs – Material: 18/8 stainless steel with copper coating (dishwasher-safe); Capacity: 1l; Size: 23 x 12 x 11. It’s an excellent feature on the 1000ml flask, which although feels a bit top heavy, is lightweight overall and also comes with the option of an adjustable shoulder strap. Within its stainless steel construction is a copper lining, although there’s no metallic smell on opening. The flask is wide enough to be used as an insulated lunchbox, too, but you would need to bring your own spoon.It does keep hot drinks hot for 12 hours, but it’s on summer adventures that this flask really comes into its own, keeping iced drinks cold for more than 24 hours. Stews and soups stay very hot all day, while fruit and tubs of yoghurt stay cool all day – or fridge-cold if you include an ice pack in the flask.