This lightweight Active Eye AELC green LED cap light is ideally suited for viewing plants at night while providing hands-free illumination. Simply clip the light device to the under brim of your baseball cap or headwear. The six long lasting LEDs allow you to check on your grow room without disrupting the flowering cycle with bright overhead lamps or fluorescents. It features an easy thumb-switch operation which can be modified with its four individual settings. This useful cap light includes 2 lithium batteries.