E.FLEX5 Monocrystalline Portable Solar Panel with USB Port The Renogy E.FLEX5 Monocrystalline portable solar panel is the perfect companion to the off-grid traveler. With a water-resistant and durable exterior, this panel can go anywhere you do! It uses auto-optimization charging which allows for automatic continuous charging once back in sun light. For flexibility with mounting, two carabiners and four suction cups are included. You can attach your E.FLEX for hands-free hiking or make your very own window charger. Charge any portable USB device with this convenient new power source! Key Features High efficient black Monocrystalline solar cells Lightweight, Ultra thin Water-resistant Auto-Optimization Charging: No charge delay when moved in and out of sun Different mounting options included Compatible with any USB device Overcharge Protection