Portable USB Electric Heating Pad Cup Warmer Coaster for Home Office Product Information USB Cup Mug Warmer: 55 constant temperature heating, small size, compact and easy to carry, support for automatic power off protection, which is reliable to use. USB Powered: USB interface for safe power supply, can be connected to mobile power supply and laptop computer, convenient for outdoor use 5V-2A. Easy to use: Intelligent control of multiple temperature adjustment, three levels temperature adjustment: can set an hour to drink water reminder.Simply plug the cord, tap the switch and put your mug on. Widely USE: Suitable for most stainless steel cups, ceramic cups, glasses, metal cups, etc. Fit for Coffee, tea, milk and other drinking you want to keep warm. Frequently asked questions 1.When there is no cup, it is normal for the three lights to flash together 2.When there is no cup, a light is on and the gravity switch is pressed to 3.When the cup is placed, the three lights flash together because the gravity switch is not in contact with it. 4.The three lights flash back and forth because the current is insufficient, and a 5V-2A plug is required 5.There are only two keys that can be pressed, one is the water cup on the left and the other is the rightmost key. The other keys cannot be pressed because the current is not enough. Solution 1.Press the bottom switch to try 2.Use 5V-2A plug, original data cable Package include:1 x Heating Coaster(Without Cup) Note: 1. Due to the different monitor and lighting effect, the actual color of the item may be slightly different from the color shown on the pictures. 2. Please allow 1-3cm error due to manual measurement. (1 inch = 2.54 cm) Thanks for your support :)