SAFE MATERIAL: The dog squeaky balls are made of non-abrasive original tennis ball felt, which is more durable than traditional tennis balls toy. The inside of the dog tennis ball is filled with non-harsh dye and synthetic rubber, allowing the dog to play without harming his teeth or eyes. | APPLICABLE RANGE: The tennis ball for dogs is in diameter 2.5", the perfect size fits with ball launchers and is suitable for training and chasing dogs of all sizes, breeds and sharps. Each package contains 4 tennis balls for dogs. exercise & fetch training | SQUEAKY BALL: The squeaky dog tennis balls also have squeaker inside the ball to induce dog's play and satisfy dog's natural instincts during the outdoor exercise and fetch training. | CHEW GENTLY: The high bounce dog toy balls are not indestructible just like every other toy. When the dog plays with the dog catching ball, avoid the interactive dog toy damage caused by chewing too hard. | WARM TIP: We guarantee that SKIPDAWG dog squeaky tennis balls will be kept under brand new condition. Please be advised should you spot any damage on product upon on the day of receipt please kindly contact our customer service team, we will be willing to help at anytime.