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It’s durable, has a great lineup of lids, and keeps our drinks hot or cold for hours on end.

The Takeaway: After running it through the gamut of testing, we can vouch for the 36-ounce Otterbox Elevation’s excellent thermal retention—we’ve woken up to ice cubes still in it from the previous day. And the wide range of available lids allowed the vessel to adapt to the setting, whether that be hiking trails or a makeshift bar during happy hour.

During a recent workday lunch break, I had just finished a punishing virtual workout. It started with a two-minute wall sit, so it shouldn’t have come as such a shock when my legs felt like jelly halfway through. At one point, I feverishly looked around the room for a half-filled water glass to quench my thirst. No dice. Finally, the hour was up. Relief flooded in, partly because I knew what was waiting on my kitchen counter: Otterbox’s Elevation growler filled with 36 ounces of ice-cold water.

The Elevation has been our Editors’ Choice pick for best thermos since late 2019 when we first tested it. I’ve spent more than a year looking for its equal and have come up empty-handed. That’s saying something considering the superb vacuum-insulated bottles from heavyweights like Stanley and Hydro Flask. Like those models, the Elevation has strong thermal retention for hot and cold beverages. But it edges out its competitors thanks to its excellent durability and expansive lineup of lids that transition the Elevation from water bottle to coffee vat to cocktail shaker.

Otterbox got its start making water-resistant storage boxes but is best known today for its near-indestructible phone cases. The Colorado-based company imparts a similar level of durability to its drinkware. The powder-coated stainless-steel exterior on the Elevation has held up remarkably well in the year I’ve had my test sample. There’s only a couple small scratches and no dents or dings.

Inside, the double-wall, vacuum-insulated design features a copper lining to boost the thermal performance. Copper is a highly conductive material, so it heats up quickly and reaches temperature equilibrium with beverages faster than stainless steel or glass. Although this noteworthy detail surely contributes to the Elevation’s stellar results in our temperature testing, the bottle wasn’t unbeatable. Other thermoses outperformed the Elevation, but not by much (more on our findings below).

The biggest complaint I can lodge against this bottle is its size. The Elevation is almost comically big—taller, wider, and heavier than the largest capacity thermos we’ve tested, a 40-ounce Hydro Flask. On our scale, the Elevation weighs 1.5 pounds. The next heaviest models clock in at 1.1 pounds. The broad base also doesn’t lend itself to storing the thermos in cup holders or water bottle pockets. I’ve been able to squeeze it into some larger mesh pockets on a couple of my hiking packs but just barely. Given its weight and storage limitations, however, I prefer using the Elevation indoors or toting it short distances, like to neighborhood parks.

Still, there’s one advantage to the gargantuan size. The wide-mouth opening is large enough for me to reach into and scrub the interior of the hand wash-only bottle. People with larger hands might not be so lucky as to benefit from this, and they’ll be well served by a bottle brush. If you’re on the hunt for a smaller or lighter thermos, consider the 28-ounce Elevation instead.

We gauge the thermal retention of thermoses first by filling them with boiling hot water, measuring the starting temperature with an infrared thermometer, letting the closed bottles rest for 24 hours, and then checking the water temperature again. In the second part of the test, we repeat this protocol but with refrigerated water. Lastly, we calculate the temperature change with each set of readings. Smaller numbers for both the hot and cold test indicate better insulating power.

Per our most recent testing, the Elevation ranks third in heat retention and fifth in cold retention of the eight bottles. The hot water cooled 65 degrees after one day, which is 5 degrees colder than the Avana 32-ounce Beckridge, the test’s top performer. In the cold test, water inside the Elevation warmed by 10 degrees compared to the 3.4-degree change of the chart-topping Hydro Flask 40-ounce Wide Mouth.

Zooming out to all 30 thermoses we’ve tested since late 2019, the average temperature change is 87.5 degrees for the hot test and 9.9 degrees for the cold one. It’s clear then that the Elevation is one of the better choices for keeping coffee or other drinks hot all day long. As for cold beverages, its performance is just average. But when average means 40-degree water warms to 50-degree water after 24 hours, we’re plenty happy with that.

What really put the Elevation ahead of competitors is its five user-friendly lids, which are all compatible with Otterbox’s 28-ounce growler and its 16- and 20-ounce tumblers. The thermos comes with a classic screw top that features a full-width handle large enough for me to fit my whole fist around. That makes it easy to twist off the top, and I worry less about dropping the bottle since it’s comfortable to hold.

Otterbox offers four other lid styles, sold separately. The Thermal Lid, which includes an eight-ounce cup, has been a welcome addition for cold-weather picnics. If you’re prone to accidentally spilling water on yourself, consider the flip-top Closed Lid or chug-style Hydration Lid that both have smaller openings. The flow rate on the Hydration Lid isn’t as fast as other chug caps we’ve used but still respectable. I liked its large loop handle that tucked away easily when I didn’t need it. Lastly, there’s the Shaker Lid that transforms the Elevation from thermos to cocktail shaker. It’s not a necessity, but it performed more reliably on a week-long vacation than some actual shakers I’ve used at home. Plus, it saved me from schlepping yet another container 800 miles to my family’s cabin rental.

Thermoses are multipurpose drinkware to begin with, but Otterbox ups the ante with this great lineup of accessories. The easy-to-use lids make an already dependable, affordable bottle stand out in a crowded field. They’re one more reason the Elevation has defended its Editors’ Choice badge.