iMeshbean Dog Training Collar with Adjustable Sensitivity Control, an and Effective Pet Training Device for 25-120 Pounds Dog, Keeping a Quiet Environment At Home/indoor High-quality Electronic Anti-Bark Dog Collar and Sends harmless warning sound and shock to the dog whenever it barks Sensitivity switch freely adjustable for the different sizes of dogs barking and specific environment Extremely small and light weight,collar length can be adjusted to 18 inch,effective on a 25-120pounds dog Controlled: Microprocessor,Comes with a 6 volt battery The collar can distinguishing the dog's bark from other environmental noises and automatically delivers sound and shock after each bark, increasing sound and shock stimulation gradually as the barking persists. NOTE: Don't encourage you to use it for puppy, especially below 20 lbs, the collar is a little large for the puppy/small dogs and the stimulation will be a little strong