Allnice&reg; 3 in 1 USB HUB 4 Port Mug Cup Coffee Warmer Heater Coasters with Digital Clock Calendar (Black) With this convenient cup warmer you can have a constantly warm cup/mug of coffee or tea. 3 in 1 product, time display, temperture of cup warmer display and 4 USB hub. Heats and keeps beverages warm at 50~60 degrees (celsius). 4-port USB 2.0 hub for powering other USB devices. The cup/mug warmer has black tone insulation material around the metal heating plate for safety along with a red status light to let you know when the heating plate is active