Exclusive Features Nano Technology - the smallest Bark Collar available  Patented Perfect Bark detection ensures your dog's bark is the only sound that will cause the correction  Automatic Correction Level adjustment - The Temperament Learning System Ten Levels of Light-Touch correction Durable, waterproof Receiver Collar Adjustable collar for neck sizes up to 16 inches with the QuickFitâ„¢ Buckle Two collar LED for good/low battery indication Lifetime Warranty  BUY EXTRA BATTERIES~~!! ONLY !10 FREE SHIPPING ON ITEMS OVER $50 ASK ME~!! "In a Tuskegee University study of adult shelter dogs wearing the PetSafe Bark Control Collar for six 30 minute sessions over two weeks, we detected no long-term adverse affects, and all dogs dramatically reduced their barking by the second day." Dr. Janet Steiss and Dr. Caroline B. Schaffer Tuskegee University   AUTHORIZED DEALER On May-14-08 at 17:10:42 PDT, seller added the following information: THE FREE SHIPPING COMES FROM PAYING FULL PRICE- OTHER OPTION FOR THIS CONTACT ME AND I WILL DIRECT YOU TO MY PRO STORE TO BUY-AND RECIEVE THE FREE SHIPPING