We have lots of these balls at the shelter and the dogs love them! They are great fun and they love tossing them around. Some of the dogs do rip off the felt on the outside so they should be monitored. But, overall they are inexpensive and lots of fun!!
we also use tennis balls for our dogs. just be careful that they aren't having a bad day and chew into the center without you knowing it. it can happen very quickly with larger dogs