DT Systems 9 Intensity Level No Bark Trainer Collar System utilizes a one-half second stimulus with a four second safety delay between stimuli if the dog barks during the four second delay the collar will not activate System is activated by vocal cord vibration only and cannot be activated by extraneous sounds 10 levels of intensity When used properly the 190dt is completely waterproof. Lightweight training collar Fits medium to extra large dogs Nine adjustable levels of intensity Completely waterproof Uses a 9 volt battery