Save space by adding the thermal cap to your Yeti bottle. As an insulating lid, it keeps your coffee, tea or even whiskey at the perfect temperature. And when you twist it off, you have a double-walled, vacuum-insulated mug. With this lid, you can enjoy your drink really hot. Whether you're on the slopes, on the boat or at work, the important thing is not to burn your tongue. Do not use the Rambler® Bottle Cup Cap with carbonated drinks or for storing food or perishable goods.