Don't worry about your hot drinks going cold any longer; warm yourself and your drinks up all day by using the Koolatron 12V/USB Heated Travel Mug! Designed to produce consistent heat, this mug has a warming feature that is activated once it is plugged in. Simply attach the USB cable to your mug, and plug into any USB port or 12 volt charger and you can keep your drinks warm all day long! This silver mug is made of stainless steel, and designed with a double wall vacuum insulation to retain heat.