Features: This Anti-Bark Collar stops barking with progressively increasing sound and shock which is controlled by a microprocessor distinguishing your dog's bark from other environmental noises and automatically delivers sound and shock after each bark, most of the pets will quickly understand the new sensation is telling her to be quiet. It can be adjusted to control the sensitivity of the voice, according to the size of dogs barking. 1. new model bark collar was updated with improved anti bark chips which will be more human? effective and easy to use. 2. 7 sensitivity levels (17) adjustable for the different size of dogs barking and specific environments through the "+"/"" button. 3. The stimulations repeat through 7 correction level? the intensity gradually increases until the dog stops for thirty seconds. 4. Lightweight receive? unique bark terminator? effective on a 120 pounds dog. 5. Adjustable nylon collar senses vibration in dog's throat during barking. How to it works: At the first bark, the 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. If your dog continues to bark, the more intense sound and shock are applies until your dog stops for thirty seconds, and then it will automatically resets to the first "tone only" level of correction.If the continuous stimulus reaches the 7 levels, then the Collar will stop working for 1 minutes to protect the dog. There is a test light which you can contact the electrodes (on the collar) and the wires (in the tester), then blow air into the sensing hole (between the tow electrodes),the light will start to light up on your 3rd time to blow, and will be brighter and brighter on your following times to blow. Description: Brand: Anpro Name: Anti-Bark Collar Material: Pastic Color: Black Size: Adjustable Battery: 6V, 4LR44 batteries required(not included) Package included: 1 x No bark receiver(Battery not included) 1 x Adjustable Nylon Collar 1 x Test Light 2 x Long shock electrodes 2 x Short shock electrodes 1 x English Manual Note: when first using, you should check under the dog's neck to make sure there's no wound. It's also a good idea to brush their coat and check their skin daily.