Make and enjoy your tea in the Nordic kitchen Thermo Tea Mug , which has double-walled vacuum insulation that keeps your tea hot for hours. The built-in tea filter in the lid makes it easy to brew your favorite tea directly in the cup. It is completely watertight, and it’s easy to take with you on the go. Designed to fit most cup holders, its functional click-open lid it is easy to use with just one hand. The cup can also be used without the tea filter for hot coffee or cold water.