marsboy 15 W Solar Charger for Cell Phone Waterproof Solar External Charger with 2 USB Port Portable Solar Charger for Hikers Solar charger for cell phone: Constructed of the 15 watts High efficiency Sunpower panel, the power conversion rate increases up to 21%-24%, providing enough power to charger 2 devices at same time. "Portable solar charger: Foldable design, easy to carry around, great for any outdoor trips or activities. Dual-Port Power - 15 watt with max 3.5 A total output to charge two devices simultaneously and save you time." Solar external charger: Water-resistant and mould-resistant nylon to endure all weather conditions. iSmart technology ensure 100% compatibility and fastest charging speed for your smartphones, laptops, tablets or other devices under outdoor circumstances. Constructed of marsboy solar arrays. High conversion solar charging technology keeps your device powered up with free limitless solar power.