Handy strobe for evening flights and to let others aware of your position. This 4 1/2 in. X 2 in. diameter strobe device emits a pulsing white light that is visible for up to 3 miles. It flashes 50 to 70 times per minute and will last for up to 60 hours. It is powered by a single D cell Alkaline battery (not included). It is also durable and waterproof.