These battery powered LED strobe lights are a great replacement for glow sticks or other light based signaling devices. Great for Lobster, Crab hoop net fishing or any other uses where a flashing light is suitable for marking a location They can be seen at an approximately 3/4 to 1 mile in favorable conditions. These Lights have an internal sensor that turns off the strobe during daylight. With fresh batteries, these strobes can function for over a week of continuous use. With proper care, this product should have an extended lifetime. These strobes are intended to be inserted into a lobster buoy to mark the location of the hoop net. Not for continuous submersion.