Features: 1. The magic ball is made of high quality material, durable, not easy to break, reusable and durable. 2. Reduce separation anxiety: Rollerball is designed to keep your pet busy and reduce stress when you ignore them. It is perfect when you are at work, have important tasks or just relax and enjoy a quiet moment. 3. Promotes strong mental health: It's not uncommon for our dogs to get bored, especially when they're home alone all day long. Designed with interactive features to stimulate your pet's natural instincts to play, it's perfect for keeping our pet happy and energetic 4. Built-in battery powered motor: It rolls automatically from inside the motor. Just unscrew the ball, plug in an AA battery, click the button on top and watch your pet play for hours on end 5. Automatic movement and interaction: the sweeping plush ball rolls automatically Its unique interactive features pique your pet's curiosity and keep them engaged. 4 Machine Washable Covers Included: Each ball contains 4 different machine washable covers. Please note: 1. The actual color may be slightly different from the picture due to different monitor and light effects 2. Please allow 1-3cm deviation due to manual measurement Material: plush + reusable plastic Size: 13.5*13 .5*13.5cm Power: 1 AA battery (not included) Package list: 1 set x Magic Rolling Ball (with 4 colors cover)