ACME Silent Whistle No. 535 The 'Silent' Dog For All Breeds Also Animal Training with Dolphins Humans (Almost) Not Audible

ULTRASONIC FREQUENCY, SILENT TO HUMANS, CLEAR TO YOUR DOG: The ACME 535 silent dog whistle operates in an ultrasonic range that is inaudible or near-inaudible to most adult humans. Your dog hears a clear, distinct recall signal. Everyone else hears nothing. The 535 is the training tool that makes whistle recall possible in residential areas, apartments, quiet streets, and any environment where a conventional audible whistle would be inappropriate. FULLY ADJUSTABLE PITCH, TUNE TO YOUR INDIVIDUAL DOG: The 535's brass screw-sleeve adjusts the ultrasonic frequency across a range of pitches. Because individual dogs vary in their hearing sensitivity, no single fixed frequency suits every animal. Adjust the sleeve to find the pitch your specific dog responds to most reliably, then condition consistently at that setting. This tunability is what separates the 535 from fixed-frequency silent whistles. SOLID BRASS CONSTRUCTION, DURABLE PROFESSIONAL QUALITY: The 535 is constructed in solid brass, giving it a weight, durability, and professional finish that plastic alternatives cannot match. The brass body holds its tuning setting precisely once adjusted, without the drift or inconsistency that softer materials can introduce over time. WORKS WITH ALL BREEDS AND AGES, FROM PUPPIES TO ADULT DOGS: The adjustable frequency means the 535 is genuinely suitable for any dog that responds to a whistle. Adjust to find the responsive pitch for your specific animal, whether a Border Collie puppy being introduced to its first recall cue or an adult Labrador being re-conditioned. Suitable for all breeds, all sizes, and all temperaments. NEIGHBOUR-FRIENDLY, PRACTICAL AT ANY TIME OF DAY: Unlike standard dog whistles, the 535 produces no disruptive audible blast. Use it at 6am before a morning training walk, in a shared garden, in an apartment corridor, or in a quiet residential park without creating a disturbance. The command reaches your dog. The noise does not reach your neighbours.