The heating pad has been carefully designed and manufactured using advanced carbon crystal heating principle to create a warm environment in winter. This is an ideal heater that will not pollute the air, safety and power saving. Easily create a very warm and spacious foot space! It is recommended for people who cannot loose their legs even if the room heating is normal.[Name:] mobile carbon crystal mat[Size:] 12" x 20", 20" x 22", 22" x 39", 39" x 39", 39" x 79"[Surface material:] Floor leather[Control:] Thermostat[Main material:] carbon crystal film[Type:] Mobile Carbon Crystal Underfloor Heating[Heating body:] heating film[Thermal controller:] Intelligent temperature control with digital display[Usage:] Office, Internet, homework, watching TV, eating, children playing and heatingPrecautions:1. The mat must be placed on a hard surface and can not be used in soft places like duvets.2. The mat cannot place objects that are not good for heat dissipation for a long time during use, and it needs to leave enough space for heat dissipation, such as a table with four legs, can use