Grades 3 & up. Realistically detailed miniature plastic model includes a stand, a fact guide and photo-illustrated assembly instructions. Features superior and inferior venae cavae, right and left atria, tricuspid valve, right and left ventricles, pulmonary artery, mitral valve, aortic valve and aorta. Opens when assembled so students can explore from the inside. 29-Piece model measures 5"H when assembled.