No Bark Collar by Street Smart Pets - Safe Anti Bark Collar for Your Dog - Bark Control Collar - Voice Activated No-Bark Dog Collar - 24 Month No Excuse Guarantee COMPLETELY SAFE FOR YOUR DOG - The technique of progressively increasing sound and shock is more effective in breaking the barking habit than conventional shocking bark control collars 7 ADJUSTABLE SENSITIVITY LEVELS - At the first bark, the Street Smart Pets Anti-bark Collar applies a short warning tone. If a second bark occurs within thirty seconds, a more intense tone is sounded. From the third bark, a more intense tone is sounded along with a short, mild shock. This pattern is repeated through 7 correction levels BARK ACTIVATED PROTECTION MODE - The Street Smart Pets Anti-Bark Collar stops barking with progressively increasing sound and shock which is controlled by a microprocessor distinguishing your dogs bark from other environmental noises and automatically delivers sound and shock after each bark. ENGLISH INSTRUCTION MANUAL - Step by step easy to follow instructions 24 MONTH WARRANTY - If you're not happy, we are not happy! If we can't make it right and you are not satisfied for any reason, we will gladly and promptly refund your purchase price! We promise.