Electronic constant temperature coaster

Function: Keep the cup at a constant temperature
 Material: Metal
 Size: 10.3cm diameter, 1.6cm thick
 Product power: 5W
 Product current: 1000mAh
 Product voltage: 5V
 Weight: 115g
 Color: wood grain / white porcelain grain / water drop grain / matt black
 Printing: Can be silk-screened / laser LOGO