Adjustable-opening treat ball - put your pet favorite kibble or small treat (diced carrot, or dried fruit or herbs) inside the hollow ball, adjust the opening to control flow of treats.$Interactive treat - roll and push the treat ball, food falls out, thus encouraging more play.$Three colors and two size - try different treats for your pets.$Good boredom buster for guinea pigs, rabbits, rats, hedgehogs and other small pets. Keep your pet entertained for hours stimulating their mental and physical.$Size 2.8-inch/7.5cm diameter