Ortz Dog Whistle to Stop Barking - Bark Control for Dogs - Patrol Ultrasonic Sound Repellent Repeller - Silver Training Deterrent Whistle - Train Your Dog UTTERLY EFFECTIVE - the Ortz dog whistle is very effective when proper training guidelines are followed. Its the best choice for training dogs to follow commands, varied sequences! EASY TO USE - clear and easy to follow instructions, easy to use for anyone  from kids to adults. Works great all the time! This dog whistle is arguably the easiest ways to communicate with your dog. CONDUCIVE  no noisy or loud, you can barely hear the sound. Can be used in public places, produces an ultrasonic burst that dogs can hear. Number one accessory to control excessive barking. COMPACT SIZE - small and compact enough to carry in your pocket, control and command your dogs on the go with this convenient Ortz ultrasonic dog whistle. ADJUSTABLE FREQUENCES - this ultrasonic whistle allows adjustable pitch. Easily adjust frequency to issue various commands. Use different frequencies for different commands!