KAUT Giant Tennis Ball Dog Toy for Playing and Training Outdoor or in the Home – The Best for the health of a Dog 24 cm Diameter : Amazon.co.uk: Pet Supplies
Chuckit! Tennis Ball Dog Toy Durable Fetch Dog Ball Launcher Compatible, Pack of 4, Medium (6.5 cm) : Amazon.co.uk: Pet Supplies
KONG SqueakAir Tennis Balls: Multi Packs
Blue Mini Tennis Ball 40mm
Tennis Ball Specifications Defined for Four Types – Balls.com – Index of Balls used in Sporting Games and Events
Tennis Ball Size & Information Guide | Net World Sports