After weeks of testing, our favorite flask is the Miir 23 ounce which fits perfectly in the exterior pockets on most hiking and urban backpacks. If you want something more colorful or rugged, we have suggestions as well. We promise these flasks will accommodate those thirst-quenching quaffs.

We’ve covered Miir’s tumblers in the past, and the company also offers some impressive, insulated water bottles. To maximize the insulation properties, many double-walled vacuum style water bottles tend to be rather bulky. The Miir 23 ounce, on the other hand, is under three inches in diameter and just nine inches in length. This allows the Miir 23 ounce to slide into most exterior backpack pockets with ease.

This formidable flagon doesn’t sacrifice insulation capacity for this svelte sizing by any means. The Thermo 3D double-walled vacuum build keeps your cold drinks cool for more than 24 hours and hot drinks up to temperature for 12 hours. As an added bonus, five percent of the purchase goes towards Miir’s Active Giving Project, supporting a host of initiatives from a bikeshare in Zambia to a clean water program in Liberia.

Yeti is well known for its durable and even bear-proof lineup of accessories, such as great outdoor coolers. The company recently unveiled its latest over-engineered series of insulated bottles capable of withstanding just about anything you can literally throw at it and the Rambler 26 ounce is one of our favorites. The three-finger cap handles grips easily during transit and the extra wide “over the nose” opening is perfect for thirst-quenching gulps and easy cleaning.

The stainless steel build is puncture- and rust-resistant, and also sweatproof to “keep your fingers dry and unfrostbitten.” Kick it, shoot it, hurl it off of a mesa — the Yeti Rambler handles the toils of the trail and then some. We’ve covered the larger Rambler jugs in the past and we highly suggest giving these models a look if you’re in the market for a larger bottle for extended weekend outings.

Today, an insulated water bottle isn’t meant specifically for a weekend outing or a trip to the gym. Many of us tow our decanters with us to the workplace, in transit, and all of those places in between. That said, many individuals seek a water bottle with a little style. For these fashion-forward quaffers, the Hydro Flask 21 ounce Standard Mouth Bottle is a cut above the rest. Available in seven sizes and more than 14 colors, the hardest part may be boiling down the options to a single build.

The Standard Mouth bottle isn’t all glitz by any means. The TempShield design keeps beverages chilled for up to 24 hours and warm for 12. The build also eliminates condensation so you won’t have to worry about rings on your desk or keeping your belongings dry. This unit is also compatible with either of the Hydro Flask caps adding a healthy dose of versatility and pragmatism to this stylish model.

Klean Kanteen released its staple canteen more than a decade ago and now, the company combined its original Klean Kanteen with a double-wall, vacuum-insulated design that’s hard to top. The Klean Kanteen Insulated Classic keeps drinks hot for up to 20 hours and iced drinks cold for an unheard of 50 hours. The wide mouth handles cubes right from the freezer and rounded internal corners make the unit easy to clean. If premier insulation is your objective, the Klean Kanteen is as good as it gets.

Many insulated water bottles use a double-wall vacuum design. This vacuum creates an insulated buffer between the internal compartment and the external environment. This small barrier greatly increases the time that warm and cold liquids maintain a desired temperature.