Unlike traditional rubber bottle, Pocket like Heating Gel Pad can be used for 2-4 hours continuously after a single charge of 3-4 mins, Auto warm function : on completion of charge, Gel Pad automatically disconnects from power on attaining required temp -75 degree.,Charge for 8-12 minutes and the gel remains warm for the next 2-4 hours. This makes it the best portable rechargeable heating pad with no smell and no side effects, easy to use and carry. Shock proof charge like mobile anywhere in hotel, train, airport, office,hospital, etc., less electricity consumption for quick relief from - backaches, sprains, muscular and joint pains, abscesses, boils and women related pains. Works great as hand/feet and body warmer also. Easy operation - does not require filling of water/liquid. It contains permanent pre filling solution.