Stainless steel is an effective material for insulating ... travel mugs should be at least rinsed out after each use, even between cups, to keep them fresh, and preferably fully cleaned once ...

Stay hydrated all day long with the classic Owala 40 oz Tumbler.

Another stainless steel option, this cup holds 12 ounces. It also has a reinforced lip to keep the opening perfectly round and a footed base for stability, according to the brand. This cup should ...