4pcs 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 to adjust while blowing the whistle until you find a frequency that you want your dog to be able to respond to. Ultrasonic Transmission - Train your puppy with an ultrasonic whistle. Effective Training - Train your puppy with different commands to make your pet follow your instructions, such as remember, sit, come, stop, bark, stay and potty. Well-designed - The dog whistle is made of stainless steel, coated with rust protection, a set of 3, durable and sturdy, small and lightweight, about 8.5 cm long.