FeaturesBuilt-in Ammeter: The ammeter of this 28w solar panel charger can measure the current real-time value. Note that the value depends on your connected devices, sunlight intensity and cable used. If your device has an input current of 1A (such as the iPhone), the amount of ammeter will show between 0.8A and 1A in theory.Exclusive Smart IC Technology: With the built-in intelligence chip, our solar phone charger detects your device then deliver its fastest possible charging speed(single maximum usb output up to 5V/2.4A, dual maximum USB up to 4A). Dual-port applies to all the 5V Android devices and apple devices. Note: This solar charger is not compatible with the iPad Pro.High Conversion Efficiency: SunPower Solar Panels with higher solar conversion efficiency by up to 24%.4 carabiners allow you to hook your solar charger everywhere convenient to get solar access (trees, backpacks, vehicle, etc.). With compact size (11.1 6.3 1.3in folded) and lightweight (21.0 oz) design, this folding solar charger is easy to carry for any outdoor activities such as camping, climbing, fishing etc.Special PET Polymer Surface: Industrial-strength PET polymer fabric protects your portable solar panel charger and your devices from occasional rain or wet fog. IPX4 waterproof level, but the USB ports and ammeter are not water-resistant, so keep them away from water while using. The pocket with a zip will keep your devices safe and clean while camping.Easy to Use: Please unfold four solar panels under outdoor direct sunlight( No cloud and no shadow), then connect your device to the usb port with your certificated cable. A micro usb cable is provided in our package. Note: Please don't place the device inside the pocket attached when charging in order to avoid overheating then damage your devices.Specifications:Colour: BlueProduct Dimension: 28.5 x 16 x 3.4 cmProduct Weight: 595 gConnectivity Type: USBSpecial Features: Portable,Lightweight,WaterproofWatt per Solar Panel: 7WNumber of Solar Panel: 4 (4 x 7W = 28W)Number of USB ports: 2Power Output: 5V/2.4A (per USB port)Total Power Output: 5V/4ACompatibility:Our product is compatible with most Apple devices, please use the original Apple cable. (Not Included)Any cloud cover arrives it may knock the value of ammeter down. We suggest you to replug the device and reopen the solar panels to reset the power controller.This 28W solar charger can't charge the laptops and power station.Notes:28W refers to the power of the solar panel, which is not equal to the actual output power of the USB port, because there will be some loss in order to maintain voltage stability and safety of equipment during the charging.Our solar charger can't store the electricity, pls unfold four solar panels under the direct sunlight and then connect with your device.Please remember that Apple's devices has an inner chip that will stop the charge whenever its inner temperature gets too hot.To prevent charging the phone under the sun, we suggest to use a longer cable and keep the phone in a shadow area.Our solar panel charger isn't suitable for small current charging products (standard charging current is below 200mA), which will be continuous shutdown and restart.Our solar charger isn't compatible with the iPad Pro.If the sunlight is not enough, your cellphones will show message "accessory is not supported".Warning: Due to the small dimension of this product, we recommend keeping it away from babies of 0-6 years old.