Bionic Balls for dogs by Outward Hound BIONIC RUBBER: BIONIC products are made with highly durable and proprietary BIONIC Rubber and are designed, engineered and quality-assured in the USA. BIONIC RUBBER is formulated without stuff you don’t want your dog chewing on like BPA, lead, and phthalates and is durability tested by an International Standard ISO/IEC and NADCAP accredited USA laboratory. MORE ENGAGEMENT: Unlike traditional treat stuffers or a standard tennis ball, the BIONIC Ball has a central treat pocket that is perfect placing your dog’s favorite tasty treats, keeping them occupied, engaged and tails wagging. Bounce, Fetch & Repeat. The BIONIC Ball brings tail wagging durability to hours of tough play and fetch games. Bring your dog’s new favorite ball to parks and beaches and it even holds treats. The medium size BIONIC Ball is sized to fit most ball launchers. Medium Size Dogs: 15 – 35 lbs. 7 – 15 kg.