The Orbit Molecular modelling set is easy to use and durable. The building system allows you to create accurate 3-D representations of all commonly model compounds.The Orbit building system uses 1cm atoms colour coded according to 12 different elements with prongs set at the correct bonding angles.The set contains 500 atoms 320 bonds and an instruction booklet. The contents allow you to cover topics commonly studied at advanced level college and university. These included saturated hydrocarbons unsaturated hydrocarbons cyclic hydrocarbons functional groups in organic chemistry benzene polymerization optical isomerism simple inorganic molecules and complex ions.Supplied in a compartmented box.