Jedzillas Puppy Products Dog Training Whistle, Lanyard and Training Guide. Adjustable Ultrasonic Pitch for Long Range or Silent Use Indoors 7cm Long Audible to dogs for up to 800-1000m or one half mile for reliable long range obedience training or recall Adjustable ultrasonic pitch allows only slight noise when blowing for indoor use but your dog can still hear it Helps you train your working dog or pet obedience, recall, sit, stay by grabbing their attention Made from durable metal with a lifetime guarantee and only 7cm long for maximum portability Make your life easier and your dogs life safer by training them to come back to you when you need them to.