E.FLEX10 Monocrystalline Portable Solar Panel with USB Port With 10 watts in this durable and portable panel, you will never have to worry about a dead battery! Perfect for on-the-go activities, this lightweight panel is sure to give you power right when you need it. The Renogy E.FLEX10 Monocrystalline portable solar panel includes two carabiners that can easily attach your panel to a backpack while hiking and four suction cups for easy mounting on vehicle windows. The built-in monocrystalline solar cells give maximum efficiency and the new auto-optimization charging feature allows for a continuous charge the moment you're back in the sun! Add on a Renogy Drifter (portable battery bank) for back-up power in the shade or at night. Don't be left without power! This ultra-thin panel is sure to charge any USB device. Key Features Auto-Optimization Charging: Continous charging once back in the sun Ultra-Thin Lightweight Water-Resistant Overcharge Protection High efficient black monocrystalline solar cells Included carabiners and suction cups for easy attachment