Rescue Lasers are hand-held nighttime laser signaling devices that provide a convenient, effective way to signal a rescue party 20 to 30 miles away. The waterproof, rugged design combines the safety of a laser-signaling device with the convenience of a flashlight. Unlike flares, the Rescue Lasers are non-flammable, non-hazardous and can operate continuously for hours on replaceable batteries. Rescue Lasers are a valuable addition to your safety and survival kit at just twice the price of two parachute flares. Rescue laser light: * 40 hours battery life * Waterproof to 80 feet * Machined aircraft aluminum * CR123 Lithium Battery * Long life red laser diode - 10,000 hours mean time life * 3.125" long.