Curtail your dogs excessive barking with this harmless, easy-to-use nylon collar. Insert the included 6-volt battery into the lightweight receiver, and fasten the adjustable collar around the dogs neck. When the dog barks, the collar senses the vibrations in the pets throat and emits a mild static shock and an audible warning beep. There are 6 progressive correction levels, so if the dog barks again 3 within 3. 0 seconds, the next Shock will be stronger, though not too strong for small or timid dogs. For safety, if the dog barks 15 times in less than 50 seconds, the collar shuts off automatically for a period of 3 minutes. The collar is designed to train the dog, not punish it, and the shocks are not harmful. According to a Tuskegee University study, adult shelter dogs wearing the Safe No-Bark Collar for 6 3 0-minute sessions Over a 2-week period showed no long-term adverse effects, and they all reduce their barking by the second day. The 2.3-ounce receiver works with dogs weighing from 15 to 120 pounds. It is water-resistant and not affected by rainy or snowy conditions. The pure digital signal eliminates interference from stray signals, and is approved by the FCC. The collar includes Pets limited lifetime warranty.