Wholesale 5 Pcs Cup Warmer and USB Hub with Clock At a Glance... Convenient USB powered cup/mug warmer. Heats and keeps beverages warm at 50~60 degrees (celsius). 4-port USB 2.0 hub for powering other USB devices. Manufacturer Specifications Main Function: Warming plate for ceramic, glass and metal cups/mugs Power: USB port of computer USB Cable: 36 inches (90cm) long Heating Plate Temperature: standard operation 50~55 C Systems: Windows 98SE / Me / 2000 / XP / Vista (32 bit version only) Power Source: Computer USB for warming plate and hub, button battery for clock Energy Usage: approx 2.5W Dimensions: - Heating Plate: 80mm diameter (3.25 inches) - Whole Unit: 135mm x 35mm diameter x height (5.5" x 1.25") Product Notes Four USB 2.0 ports for chaining additional USB accessories LED red status light ON/OFF warmer switch Cup warmer has four foam rubber feet to keep it firmly and securely on your desktop Package Contents Model CVSB-K22 Cup warmer Instruction Sheet - English FAQ - Frequently Asked Questions Will this work with my Mac or Linux computer? Do draw power for heating, it should work with any USB enabled computer. However, the USB hub will only work with Windows computer. Will the clock work when my computer is off? Yes, the clock works independently of your computer.