The #1 Recommended headcollar, endorsed by leading vets and trainers. Immediate, gentle control, never chokes or hurts. Stops pulling, lunging and other misbehaviors. Pressure is applied to the back of the neck, rather than the front, reducing your dog's drive to pull forward. It works like a halter on a horse, where the nose goes, the body will follow...... Has an adjustable nose loop for a custom fit. Won't come over dog's head. Converts to a regular collar for greater flexibility. Medium fits up to 25-60 lbs. Complete training guide included.