This kit is designed for individual use, and includes 6 carbon atoms, 15 hydrogen, 4 chlorine, 2 iodine or fluorine, 2 nitrogen, 2 oxygen and 2 bromine. For maximum flexibility all bonds in this set are made using springs instead of pegs. Included are 12 short springs (1") , 6 medium springs (1-18"), and 12 long springs (1-1/4"). The atom centers are 3/4" dia. and are not compatible with the Student Set. Instructions included.