The Chuckit Tennis Ball is a premium quality tennis ball with an extra thick core. Custom made for your canine! This 2 pack is strong and durable with high visibility and is compatible with the Chuckit ball launcher. Please Note** Do not leave unsupervised with your pet.Proper supervision is advised when playing with all toys to ensure no accidental swallowing. This toy should be regularly inspected to ensure there is no damage. If any damage is seen the toy should then be discarded.