The Solar Dock Post Lights™ v5 are a great way to light up your dock or pier. During the day, the solar panel collects the sun's energy and charges the batteries. At nightfall, Solar Dock Lite's sensor automatically turns on the super bright LED. With multiple units your dock will provide an elegantly lit pathway. This unit is hands free and energy efficient. Lasts 18+ hours on a full charge and is significantly brighter than conventional solar garden lights. Simple to install, install the Solar Dock Post Lights to your dock and enjoy the ambience.