The Innotek® Automatic No-Bark Collar is a safe effective way to stop excessive barking. The collar features an auto-set feature which automatically adapts to your dogs bark. The more he barks, the higher the correction. As he learns to bark less frequently, the No-Bark Collar stops at the level just right for your dog. The water-resistant lightweight collar unit features a replaceable battery with long and short contact points for varying coat lengths. Also comes with complete operating instructions and free professional training support and training DVD. Limited lifetime warranty. Can be used on dogs as small as five pounds, however the size of unit (2” x 1 ¼” x 1 ¼”) is more suited to a dog approximately 15 lbs. and up.