Poweradd High Efficency 20W Dual USB Port Solar Charger with SmartCharge Tech for iPhone 7s Plus 7 6s 6, iPad, iPod, Samsung, HTC, LG, Nexus, Gopro, MP3 Players, External Batteries and More Exclusive PowerSI Technology: It automatically adjust the current and voltage to achieve maximum power,delivering its fastest possible current up to 2.1 amps per port or 4 amps overall under direct sunlight. High Efficiency: SUNPOWER solar cell is made from US, up to 22%-25% efficiency, while most panels in the market are 15% efficiency. Slim and Powerful: 1/3 lighter than the same power of solar slicon. The total power increased by 1/3 in compare with the same solar panel size; eyeholes enable easy attachment to backpacks while hiking; Portable and frame design fits for outdoor and indoor use High Quality: PET laminated solar panels with high-wear PVC fabric, ensures waterproof and weather-resistant durability. What You Get: 20W Foldable Solar Charger,carabiner, micro USB cable, User Manual; Poweradd offers 24-Month limited product warranty, buy with confidence.