The Beacon Flashing Safety Light clips to pet collars or human clothing giving you peace of mind anytime you and your companion are out and about. The Beacon uses a LED to create a short pulse of light 120 times per minute for visibility up to 1/2 mile. Included batteries last for up to 130 hours of continuous use. Durable, long-lasting construction and waterproof to a depth of 300 feet. Lifetime LED bulb. This is the best pet strobe we have found--we use it for our daily early morning walks to alert cars of our presence. Be seen, be safe! Keep track of dogs in low light situations Clips to dog collars and to human clothing 130 hours of battery life Compact size ~ light weight Waterproof ~ submersible to 300 feet Lifetime bulb never needs replacing Length: 1.75" ~ Diameter: 0.875"