Heater
If they are the ones I am familiar with, I don't encounter them often enough, (only about once or twice), to remember the brand, they are a plastic heater that you can carry with one hand if you could get a grip on it. They are not guaranteed not to leak for a lifetime, they are guaranteed that you will get a new heater when it leaks. There is a difference. I had a customer who purchased a house partly because it had the Sears model of that heater. When it started leaking a few months later, he found out that the "lifetime" expired when the original owner sold the house. Unless they have changed their policy, you have to register the heater with the manufacturer to activate the warrany.