* WARM THE WHOLE BODY---These smart heating underwear are used to generate heat in the core parts of the body (Chest,Belly,Shoulder,Back,Waist,Elbow,Thigh,Knee,Calf) Provides a steady stream of heat in cold winter. * SKIN FRIENDLY & COMFORTABLE---The lining of the electric thermal underwear is made of comfortable Cotton provide you with all-day warmth, Can be washed by hand or machine, does not affect the heating pads. Material: 95%cotton+5%spandex, carbon fiber bundle * SMART TEMPERATURE ADJUSTMENT---App Controlled Electric thermal underwear can be heated 3-kind temperature 45°C(green light),55°C(blue light),65°C(red light), you can manually switch and adjust the temperature, Press and hold for 3 seconds to on and off. * SAFETY AND INTELLIGENCE---The heating underwears powered by 5.0V USB power banks (NOT INCLUDED), much lower than the human body safe voltage. Warm clothes allow you to enjoy warmth in the cold winter and without any safety concerns. * Carbon fiber gauze is made of far infrared heating element layer and soft skin-friendly materials to ensure comfort and warmth. Intelligent temperature control, heating on the knee, back and waist. The USB plug fits. Into a portable charger compatible with 5V/2A USB power supply (NOT INCLUDED). It starts heating within 30 seconds, lasting for a long time, and long heating time. Size runs small! This is labeled as XXL!