This single hole 17mm light green atom is not supplied with any of the standard sets but is available for sale as a standalone item. It is intended for use as the "4th" halogen so that chlorine, fluorine, bromine & iodine can all be identified separately.
Indigo Instruments has maintained a substantial inventory of genuine Molymod atoms & bonds for over 30+ years. These parts are compatible with every set & kit we have sold since day 1. Though quality may appear expensive, no parts support from other vendors costs even more.
Use only these genuine Molymod Atoms & Bonds for full compatibility with any of our Molymod Molecular Model Sets & Molymod Molecular Model Kits.