PetSafe Busy Buddy Ultra Rawhide Refill Dog Treat Chew Toys - Size D (3 Pack) Pack of 3 Small PetSafe Busy Buddy Ultra Rawhide Refill Dog Treat Chew Toys - Size D New, thicker rings for dogs who chew through the standard rings too fast 4x thicker than our regular Busy Buddy Rings Fits only Busy Buddy Ultra toys