Vktech&reg; Portable Power Bank Backup External Battery Charger Battery Pack 18650 for Phone MP3 (Black) Metallic appearance, Small and light Weight, Easy to carry around in your bag Standard USB output, Charge your portable device on the move without the need for main power Self-adaptive technique allows intelligent faster, safer charging Charging-in with USB cord(Not included), or by charging the batteries with other chargers Strong compatibility for ipod, iphone, ipad, mobile, MP3, MP4, gameboy, PDA, GPS, etc