Aqueon Betta LED Light is perfect for small desktops up to 3 gallons in size for general illumination. This small but versatile light had 3 modes LED of illumination using soft touch operation Blue only White Only All On. The light can operate using Micro USB B Cable or three AAA batteries both sold separately. When using batteries the light has a 1 hour shut off period and the Micro USB B cable provides constant power until the light is manually turned off. Not all desktops are designed the same so this light provides three ways to set up the light. Design for use on aquariums with clear lids this light can rest right on top of the lid or use the three small legs to elevate the light or use the clamp to attach and raise the light higher above the aquarium. Aqueon Betta LED Light is great for glass or plastic aquariums with clear lids.3 Modes of Illumination Blue only White Only All OnFor use with Micro USB B Cable or three AAA batteries both options sold separatelyWhen using Micro USB B cable power is constantly on when using batteries there is a 1 hour auto off featureLight can rest on top of aquarium with clear lid use legs to elevate the lamp over a clear lid or use the clamp.For use with aquariums with clear lids.