"High Efficiency Solar Panel: 5.3Watts solar panel can be removed from the backpack to use alone. The solar panel absorbs solar energy, high efficiency up to 24% transfer rate, converts into electrical energy to charge your cellphone or other small gadgets. How to Use: Please note the panel can not store power directly, if you want to store the power, you can use it to charge your power bank. Make sure the solar panel is under strong sunlight when charging your devices. If the panel can not work, please check the usb interface is plugged into the solar panel exactly. Remember remove the usb plug after work. Large Capacity: L*W*H: 30*19*47cm(11.81*7.48*18.50 inches). Large enough to accommodate up to 15.6 inch laptop, mobile phone, wallet, books, magazine, clothes or other personal items. The back zipper pocket can place mobile phones, wallet and other valuables, anti-theft and convenient. Comfortable Carrying: Padded adjustable shoulder straps are made to ease the pressure on your shoulders while carrying. Breathable mesh of the back can dissipate heat so that you would not feel too hot while using it in baking summer. High Quality Solar Backpack: Made of high quality oxford cloth, lightweight and waterproof. Perfect for business, school, college, hiking, travel, camping, day-trip and other outdoors activities. A great merry christmas gift for mens." "Product origin : China Key Specifications/Special Features : Place of Origin China Port Of Loading Xiamen Port Payment Term TT,LC,Western Union Delivery Time 30-45 days Minimum Order Size and Packgaing details : 50PCS 1pc/bag, 24pcs/ctn"