Material The whistle is made of stainless steel and plastic, safe material and fine workmanship, will not rust or fade, producing frequencies safe for dogs. It is extremely durable and will have a long lifetime. Effective Training Dog Whistle can be used to remind dogs, train them to fetch, lie down and sit, while correcting bad dog behavior. When the dog is 3-7 months old, the training effect is the best. Safe Dog Whistle Dog whistle does not hurt or disturb your dog; it just catches his attention and he stops the annoying barking. It is an ideal training tool so as not to injure your dog during training sessions. Easy to Carry The dog whistle is small and light; you can put it on a keychain or pocket. You can take it anywhere with you because you will never know when you need it. Application It is a good tool to train your dog to sit, come, stop barking and stay according to your instructions, suitable for poodle, border collie, german shepherd, bulldog , rottweiler, dachshund, huskie and others races. Package dimensions 14.1 x 10.2 x 2.6 cm; 70 grams Requires batteries No