4-Piece Ultrasonic Dog Whistle, High-Frequency Dog Whistle, Adjustable Ultrasonic Whistle for Training, Barking, Sitting, and Recalling Dogs

Adjustable Frequency: You can adjust the adjustable nut on the dog whistle by turning or unscrewing the screw while blowing the whistle until you find a frequency to which you want your dog to respond.Ultrasonic Transmission - Train your puppy with an ultrasonic whistle. Effective Training - Train your puppy with different commands so your pet follows your instructions, such as remember, sit, come, stop, bark, stay, and potty.Well-Designed - The dog whistle is made of stainless steel with a rust-resistant coating. This set of 3 is durable, sturdy, small, and lightweight. approximately 8.5 cm long.