The Double Layered effect of the 17 Stories Double Wall Coffee Mugs make it appear as though the liquid is 'floating' inside the glass and the double wall creates a thermal effect, helping to keep your cold drinks cold and your hot drinks hot for longer periods of time. This means that your cold drinks will stay bubbly and crisp, and cold, while you enjoy it, with no build-up of condensation either and hot drinks stay hot for longer, with the added benefit of the 17 Stories Double Wall Coffee Mugs remaining cool to the touch.