Features: Straps are made of supple nylon. Won't choke. pressure is applied at the back of the neck vs. the front of the throat. Not a muzzle. when fitted properly a dog can open its mouth to eat, drink, pant, fetch, and bark. Can be used with dogs eight (8) weeks of age or older. Can be worn up to 18 hours/day. Comes with easy-to-follow fitting instructions, an abbreviated training guide, and a more comprehensive training DVD and training booklet included: Why is a Gentle Leader the best choice? Here are just of few of the reasons why. Stops leash pulling. an extremely common problem that spans all breeds, ages, and activity levels and leaves both owners and dogs frustrated. Controls unwanted behaviors. general aggression and dog-on-dog aggressive behavior, anxiety issues, and a wide range of compulsive disorders. Fully adjustable. both neck strap and nose loop can be adjusted independently to create a custom fit. Immediate results. most dogs acclimate within minutes and respond very quickly. Lifetime guarantee.