Come and see our amazing products. The USB heating coaster is made of PVC material to keep the beverage on the coaster warm. It uses the computer's USB interface for power supply and can be applied to all PC and mobile. Generally, the temperature of coffee, tea and other beverages can be kept constant, and installation is simple. Accept customized LOGO. 3.5" Diameter Pls confirm with us about the packing info, stock color and exact production time before placing your order.