The PEBBLE Explorer has a large 8400 m Ah capacity & dual USB (Universal Serial Bus) port designed to enable charging of 2 devices at any one time. With a 2.1 A output the PEBBLE Explorer is designed to charge tablets in the most efficient way. This means that your tablet power is replaced as quickly as possibly when you're low on charge & away from a mains source. Don't worry if your smartphone is also low on charge because the Explorer's dual port design means it's capable of charging 2 devices at the same time. The powerful 8400 m Ah battery can give most tablets a complete full charge & most smartphones up to 5 charges. The stylish blue LED power indicator means you can keep a close eye on the Explorer's exact capacity when charging your devices & also when you are recharging your Explorer. An long hour mains charge to the Explorer will give your portable devices hours of additional usage while you are away from the mains which makes it the perfect companion for camping, trekking, festivals as well as business users who easily drain their portable devices during a long busy day.