keep Your Body And Hands Warm: Qualified Carbon Fiber Heating Elements With 3 Heating Levels To Generate Consistent Heat For 4 Core Body Parts, Including Your Neck, Back, Abdomen, And Waist, Helping To Maintain Body Warmth. long-lasting Usage: A 10000mah Power Bank Offers Up To 8 To 10 Hours Of Warmth On Average(lasting Period Can Be Vary Depending On Different Types Of Power Bank); Power Bank Is Not Included In Our Product. overheat Protection: Implanted Sensor Will Be Triggered To Terminate Heating Immediately If, For Any Reasons, The Heating Areas Internal Temperature Exceeds 150f. Guarantee Your Safety In Any Occasions. "all Products From Us Have Undergone Strict Quality Checks. if There Is Any Quality Problem Or You Are Not Satisfied With The Product contact Us. we Will Give You The Best Solution."