Orbit 3 prong black 120-120-120 degree atom represents carbon & can be used to represent molecular hybridization in molecules such as benzene. It is used exclusively in our buckyball and carbon nanotube models and is one of 4 carbon geometries found in our 12 base pair DNA model.
You can use these Genuine Cochranes of Oxford Orbit Molecular Model Parts to replace missing pieces or augment any of the Orbit Molecular Model Sets & Molecular Model Kits supplied by Indigo Instruments.