The HGS Stereochemistry Molecular Models are suited for constructing molecular skeletons, the scale of the model being 1 Å = 2.0 cm. It is thus very useful for configurational and conformational studies of organic, inorganic, and biochemical molecules. The chair, boat, or envelope inversions of ring structures can be readily performed, strained rings can be constructed without difficulty, and interatomic distance and torsion angle can be measured directly. Particularly the data are important for the analyses of NMR NOE, coupling constants, CD (circular dichroism) exciton chirality, etc. Thus, these models are well-suited for stereochemical assignments and discussions.