PetSafe Rechargeable Bark Control Collar, Waterproof, Reduce Barking 10 LEVELS OF PROGRESSIVE STATIC CORRECTION - allows you to find the right level to eliminate or reduce your dog's excessive barking 3 CORRECTION MODES - fine tune the correction for your pet including an option to increase the correction level is barking continues. PERFECT BARK DETECTION - patented system prevents false corrections from other noises including another dog barking WATERPROOF COLLAR - for all of your dog's outdoor activities FITS DOGS OVER 40 lb. - designed with big dogs in mind; Fits neck sizes up to 28" Manufacturers warranty is only valid when purchased from an authorized retailer