4 Watts high-efficiency mono-crystalline solar panel with foldable design offers excellent portability, ideal for emergency preparedness, backpacking, camping and other outdoor activities * Built-in standard female USB port for directly plugging in iPhones, Android-based smart phones, Blackberry & other USB compatible mobile devices * Charges built-in 2,000 mAh Rechargeable Battery Pack and external device at the same time * Measures only 7 ¼ X 4 ½ X 1 ¼ inches and weighs 7.6 Oz * Weather-resistant design, backed by 1-year manufacturer"s warranty