Use Solar Power to charge your smart phone, tablet, MP3 player, GPS, camera or other digital device on the go. Dual Ultra High efficiency solar panels - 21. 5% efficiency with broad light spectrum provides up to four times the charging power of traditional solar panels. Built-in cables for trouble-free charging. Recharges a cell phone up to 6 times without recharging. Dual USB ports allow you to charge two devices at once. USB 2. 0 output for charging iPads.