The cold winter days are coming soon, are you still prepare to stay in a chilly office without any solutions? Or suffering from raynaud's, arthritis, muscle pain? In all these situations, there is nothing that a hand warmer can't solve. Our hand warmer is USB rechargeable design, with 3 heating modes. It can also be used as a power bank to charge your phone, tablet and other electronics. Portable design allows you to carry it for traveling, camping, shopping, hiking, etc. Features - Color: Black. - Material: ABS, aluminum. - Size: 10.4 x 6.3 x 3.6 cm/4.09 x 2.48 x 1.41 in. - 2-in-1 multi-functional hand warmer, both great as a hand warmer, also a nice power bank. Constructed with aluminum material, shockproof, anti-scald, anti-skid, explosion proof and radiation-free. - 5200mAh capacity gives a full charge to mainstream digital devices in the market. Suitable for charging phone, tablet, GPS, MP3, digital camera, etc. - This product can be used to warm hands, feet, stomach, waist and knee at low ambient temperatures, so as to eliminate fatigue, relieve back pain. - 3 heating modes to suit your different needs, and 3 indicator lights keep you informed of the remaining battery and heating status. - USB rechargeable, blue light flashes while charging. Especially suitable for the elders, children and office staffs. Specifications: Input: DC 5V, 2A Output: USB 5V, 2A Battery capacity: 5200mAh Charging time: about 2-3h Fully charged: about 3h Charging indication: blue light flashes Size: 104 x 63 x 36 mm Net weight: about 132g Heating Modes: Low temp(38-42): 1 red light on, working for about 5-7 hours. Middle temp(42-48): 2 red lights on, working for about 4-6 hours. High temp(48-55): 3 red lights on, working for about 3-5 hours.