Oternal Electronic No Bark Control Dog Training Collar with Adjustable Sensitivity Control, Red Nylon Collar, an and Effective Pet Training Device for 25-120 Pounds Dog High-quality Electronic Anti-Bark Dog Collar and Sends harmless warning sound and shock to the dog whenever it barks The stimulations repeat through 7 correction levels, the intensity gradually increases until the dog stops for thirty seconds. If the continuous stimulus reaches the 7 levels, then the Collar will stop working for 1 minutes to protect the dog Sensitivity switch freely adjustable for the different sizes of dogs barking and specific environment Lightweight receiver, Unique bark terminator, Replaceable 6-volt Battery, Red nylon strap with 29.5 inches length, Effective on a 25-120pounds dog 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