U.S. Coast Guard approved. 4 1/4 overall. Durable orange ABS body. Pressurized Xenon gas bulb. Visible up to 3 miles depending on conditions. Operates at 50-60 flashes per minute for 8-12 hours and then switches to 20-30 flashes per minute. Ideal for all marine environments to aid in search and rescue and to mark out hazards. Waterproof to 12 feet. Up to 30 hour runtime per battery. Uses one D cell Alkaline battery (not included). Hang packaged.