Brilliant high quality stainless steel construction with stylish knurled grips and a handy to keep dust, dirt and lint out of your whistle, exquisite and practical. Wordlessly train your dog with ultrasonic sound; What sounds like a gentle whistle to humans can be heard by a dog hundreds of yards away. Enjoy training your dog, and improve your communicative bond with the whistle. Since different dogs respond to different frequencies our whistle allows you to change and adjust the whistle frequencies to suit your own dog hearing. Adjust the frequency until you find the right pitch for your dog, then lock it in with the special locking nut. This product used unique and sophisticated technology, environmentally friendly food grade stainless steel long metal chain, safty and durable. Impact discipline and personally control your dog by issuing sequences that only he/she understand, regardless of their age, gender or breed. Removable chain and key rings offer dozens of convenient carry options: in your pocket, with your keys, on a lanyard, a belt loop, or a backpack. Get a great tool to teach your dog obedience and enjoy watching him learn basic skills and even advanced movements as you whistle different commands to him. Specification: Material: Copper + stainless steel Size L Combined whistle length: approx. 10cm/3.94inch without sleeve whistle size: approx. 8.7x0.7cm/3.43x0.28inch Chain length: approx. 22cm/8.66inch Size S Combined whistle length: approx. 8.5cm/3.35inch without sleeve whistle size: approx. 7x0.7cm/2.76x0.28inch Chain length: approx. 15cm/5.91inch Package Includes: 1 Piece dog whistle Note: Since the size above is measured by hand, the size of the actual item could be slightly different from the the size above. Due to the lighting effects, monitor settings,etc.There could be some slight difference in the color tone of the pictures and the actual item.