The Sandberg Solar Charger 21W 2xUSB is a highly efficient solar panel that converts sunlight into electricity. It features 2 USB outputs that can be used to charge your USB devices, such as smartphones, tablets, or power banks. By connecting to a power bank, you can store electricity for later charging of your smartphone or use it as a stabilizing intermediary while charging if your power bank supports simultaneous power input and output. The included carabiners can be used, for example, to attach the solar panel to your backpack when you set off on an adventure. This is eco-friendly energy for your devices.