Features: 1. Made of premium material, sturdy and durable in use. 2. Easy to carry with key ring or key chain. 3. Train your pet to be compliant and teach them good behavior. 4. Easy to use, suitable for training dogs, cats and parrots. 5. Pets can reply by receiving special sound frequency, improving the interaction between pets and owners. Specification: Condition: 100% Brand New Material: Stainless Steel Color: Random Size: Approx. 11*1.5 cm / 4.3*0.6 inch Ring Diameter: Approx. 2.5cm / 1.3 inch Weight: Approx. 22g / 0.8 oz Package list: 2 * Whistle Note: 1. Please allow 0-1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. 1Made of premium material, sturdy and durable in use 2Easy to carry with key ring or key chain 3Train your pet to be compliant and teach them good behavior 4Easy to use, suitable for training dogs, cats and parrots 5Pets can reply by receiving special sound frequency, improving the interaction between pets and owners