I Heart O-Chem Molecular Model Set for Organic Chemistry, 200 Pieces Contains 116 plastic links and 83 spherical models of atoms relevant to the study of organic chemistry: carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorous, fluorine, chlorine, bromine and iodine. Also includes a link remover. Perfect study aid for high school students in AP Chemistry and college students in organic chemistry, biochemistry and other pre-med classes Enables visualization and manipulation of organic molecules (especially Newman projections and chair conformations) Durable, well-made plastic components Great, positive reviews by students, high school teachers, and college professors