YS-300 Yapper StopperBark activated no bark collar for small to medium sensitive breeds. Dogtra has developed a sound recognition and filtering micro processor that distinguishes your dogs barking from ambient noises. The YS 300 is an intelligent no bark dog collar, which is fitted with this self activating micro processing sound analysis technology. This technology allows the collar to only respond to the barking of your dog. (Patents pending.) Features seven intensity