PetSafe Busy Buddy Ultra Refill Dog Treats for Large Busy Buddy Ultra Dog Toys, Natural Rawhide, Size F (3 Pack) 3 Pack of PetSafe Busy Buddy Ultra Refill Dog Treats for Large Busy Buddy Ultra Dog Toys, Natural Rawhide, Size F New, thicker rings for dogs who chew through the standard rings too fast 4x thicker than our regular Busy Buddy Rings Made from compressed natural rawhide Fits only Busy Buddy Ultra toys