Molecular models are NOT toys and should be kept away from young children. These sets and kits are intended for educational use only.Help students understand the shapes of crystalline solids using models of the 3 cubic unit cells: cubic, body-centered cubic, and face-centered cubic. These models help students understand how to solve problems based on unit-cell properties, such as calculating atomic mass, density, and Avogadro's number, that routinely appear in textbooks and on standard examinations. Cubic and body-centered cubic models measure about 3" sq; face-centered cubic model measures about 3 1/2" sq. Order individually or as a set.