Squeaker built into the center to stimulate interest. It can makes a sound,our dogs & puppies will surely be busy and excited with it, because of sound effect, let dog feel more interested,release dog’s sense of separation anxiety, keep dogs mentally and physically entertained.We pay special attention to the dogs' health and safety. This toy is made of environmentally friendly non-toxic natural rubber, which strictly controls the safety of raw materials. Keep the dog happy and safe.