This Mug/Cup Warmer is the perfect solution for keeping your beverage warm and also working as a plugin charge center for your phone or other electronics with its 4 USB plug in areas. Enjoy a hot cup of coffee, tea, or any beverage at any time, whether it's at home or work with this cup warmer. It's extremely easy to use, just plug it in and turn it on. This single-cup coffee warmer makes a great gift for any coffee/tea lover. It can also be used to heat soup or cocoa as well. This electric warmer has a smooth, shiny silver finish and is made out of durable plastic on the outside ring and has non-skid feet at the bottom to help support your mug and prevent spills. Contains an AC adapter input (DV5.0V/1-2A), plug in cord not included. Measures approximately 3 3/4" in diameter and 3/4" in height. Plug-in cord measures approximately 36 1/2" in length. The product will fit mugs/cups with a base diameter of 2 3/4". When light is green only, this means it is on. When light is both green and red, this means that it is on and is hot.