The PetSafe PBC00-10782 Deluxe Little Dog Bark Collar is designed specifically for small dogs. It has two primary features designed to shorten the training phase and promote good behavior. First, the Bark Control Collar has a unique patented sensor that provides the most reliable bark detection available. The Bark Control Collar uses both vibration and sound sensor (dual-detection) to discriminate each bark from other external noises. A static correction is administered through the contact points only if both the vibration from the vocal chords and the sound from the bark match the same criteria. Second, the Bark Control Collar has a new patent pending Temperament Learning Syste3m design that is effective across many dog breeds and their individual barking behaviors. The Temperament Learning System contains software that tracks the number of corrections needed to substantially reduce (and in most cases eliminate) the number of nuisance barks. The system has 10 levels of static correction. It begins with low-level corrections, however, if excessive barking continues the correction intensity will increase with each successive bark until the barking stops. Once the dog has learned to reduce the barking, the initial warning corrections are reduced. As a built-in safety feature, if your dog barks 15 times or more within a 1 minute 20 second period, the Bark Control Collar will automatically shut off for 3 minutes. PetSafe PBC00-10782 Deluxe Little Dog Collar features: Nano Technology - the smallest bark collar available Patented Perfect Bark technology ensures your dog's bark is the only sound that will cause the correction Automatic Correction Level adjustment called Temperament Learning Ten levels of Light-Touch correction QuickFit™ buckle provides a quick release and perfect fit every time (patent pending) Durable, waterproof Receiver Collar Two color LED for good/low battery indicators 10 levels of correction Progressive correction feature increases correction to next strongest level if dog continues to bark Safety time out will shut off the correction for 3 minutes if the dog barks more than 15 times in 30 seconds Uses vibration sensor to sense for barking Not recommended to use for more than 8 hours at a time Lifetime Limited Warranty Receiver collar specs: Height: 1.06" Width: 1.65" Depth: 1.42" Weight: 2.0 oz. Uses a Petsafe Battery: RFA-188 (lasts 3-6 months) Waterproof Adjustable collar for neck sizes up to 16"