Material: PC material, scratch-resistantAccessories: keychain: 7.5*3.5*2cmKey ring: 2.5cmApplication: All dog breedsoduction:- 2 in 1 functional design. Press the heart-shaped switch with your hand to make a loud clicking sound. Whistling with your mouth produces high-frequency sounds, all with excellent penetrating power. This ensures that it can be used in different environments.- Efortless. When trying to survive or ask for help, you must save your energy. A good survival whistle must be able to make a sound easily.- Integrated design, sturdy and reliableciples and Methods:-The principle of training is that there will be no differences due to dog breeds or individual differences.-The training method can be adjusted according to the dog breed or individual differences.