[Longer, Safer] Max 6.5 hours, Temperature 47±2℃ for Safety
[1 Second Quick Heating & Intelligent Heat Control] The F740H Hand Warmer Portable Charger is heated instantly on both sides at a constant temp to both your hands with all round warmth, promising good heat transferring performance and longer service hours. (Max 6.5 hours, Temperature 47±2℃ for Safety)