Maintain optimal temperature: This mug warmer not only can slow down the cooling speed of hot coffee, But also can heat your coffee up to 120℉-140℉(40-60℃). and keep this temperature whole day, which is neither too hot nor too cold, you can sip your coffee at any time, without waiting.Safe & Reliable:Thanks to the microgravity technology, this coffee cup warmer can shut off/on auto. Just plug the adapter into outlet, then put your mug on and the coffee warmer will work auto, take it away, the cup warmer will off auto.The Weight of your mug needs to be over 0.8lbs (13oz) to activate the gravity induction switch.Suitable for most cups: The electric coffee warmer has 3.5" diameter heating area. It can be fit most cups, such glass cup,stainless steel cup, Ceramic cup etc. for better results, we recommend using flat bottom glass cup or stainless steel cup. Placing a lid over the mug will also help retain heat.Waterproof design: the heating plate was covered with a layer of thermal conductive glass without need for security concern for occasional spill and it is easy to clean,safe and reliable.Winter's Gift: coffee warmer keep the beverages(Coffee, tea, milk etc) warm whole day, making it a great gift for lover, dad, mom, wife, husband, grandparents and all your loved ones on Valentine's day, Thanksgiving and Christmas, and other special occasions to express your sincere care.Note: This mug warmer plate is capable of keeping your hot beverages warm enough for drinking when you used a suitable mug, please do not expect it to heat your cold beverages to scorching hot in a short time. It is designed with low power consumption to keep your hot coffee or tea always warm. Please Reach out to if you get any questions or issues when using it. Thanks for your understanding.