These 4D Vision plastic anatomy models are unique in that they show a cutaway of the animal, so you can see the outside covering of the animal on one side, but can also peer through the "cutaway" side to see the bones and internal organs. They're more than just "pretty face" models that sit on the shelf - you can open them up, take them apart and put them back together again. Made by the same manufacturer as the 4D Human Anatomy Models, the parts are realistically painted and molded, but fit together like a puzzle. The frog features 31 pieces and measures 5 ½", the horse stands 7 ¼" tall and includes 26 pieces, the cow is approximately the same size as the horse and includes 29 pieces, and the pig has 19 parts and is approximately 6" long and 3 1/2" tall.