Features:Organic/inorganic chemistry tutorial, ball stick type, proportional molecular structure model. The model set can be used to construct a variety of common and slightly complex C, H, O, N, Br, l chemical organic molecular structure models, suitable for teaching and laboratory use. The model can be used to construct structural formulas of various molecules of inorganic and organic substances in chemical textbooks. Made of environmentally friendly plastic, it is very safe and will not be broken, and has a long service life. The model can increase the students' interest in learning, and the teacher can explain it more intuitively. Very convenient. Specification:Material:PlasticH Atom Diameter: 17mmOther Atom Diameter: 23mmPackage List:86*Atom Model153*Link 1*Link Tool1*Plastic Box.