Nitey Leash is the world's first fiber-optic illuminated dog leash. Fun and fashionable, Nitey Leash helps keep you and your dog safe, visible from more than a quarter mile away in the dark. Nitey Leash is the only LED dog leash that is lighted from end to end, creating a beautiful dog leash that glows. Five Feet Long. Water Resistant. Runs on 3 AAA batteries (included). Two modes -- steady and blinking One size fits most dogs (up to 150 lbs) 90% say they feel safer by using Nitey Leash.