If a reusable travel mug is on someone's wish list this Christmas, you could be tempted to opt for a mug from popular brand Thermos.
As a well-established brand you might assume you can rely on Thermos for high-quality products, but our tests show that not all of its travel mugs are created equal.
We've tested three Thermos travel mugs: Thermos Stainless Steel King Travel Mug (£22),Thermos Direct Drink (£18) and Thermos Thermocafe Translucent Travel Mug (£10).
Two of them did brilliantly in our tests and are Best Buys, scoring 82% and 81%, respectively.
However, one failed to impress our testing experts, letting hot drinks cool far more rapidly than we'd have liked. It's our lowest-scoring travel mug of the 13 we've tested in total, with just 46%.
We've tested three Thermos mugs, ranging in price from £10 to £22. The best felt strong and sturdy, had excellent heat retention and a fully leakproof design.
The worst had poor build quality and didn't hold in heat well, so hot drinks quickly turned lukewarm.
This travel mug comes with a built-in teabag hook for on-the-go tea drinkers, and has a DrinkLock sealing lid to prevent liquid escaping. But at £22, it's more than double the price of the cheapest Thermos travel mug we've tested.
Thermos claims this travel mug, which comes with a push button release lid, is super light, leakproof and keeps drinks hot for 10 hours. We've analysed whether it lives up to claims.
At just £10, this cheap Thermos seems like great value. It has double wall insulation that Thermos says will retain hot and cold temperatures, a slide lock lid and a useful carry handle.
We've tested travel mugs from a wide range of brands including Bodum, Contigo and Nespresso and found some great options.
Our highest-scoring travel mug (which isn't from Thermos) got an impressive 85% in our tests.
Opting for another brand could also save you money - the cheapest travel mug we've tested costs just £5 from Wilko.
If you're carrying drinks on shorter distances, consider a reusable coffee cup instead of a travel mug. This is essentially a reusable version of a disposable takeaway cup, usually with a 350ml capacity (the size of a regular coffee).
Unlike travel mugs, they tend not to be fully spill-proof, though, so some liquid might escape if they're knocked.