Molecular Model Large Demonstration Set 
With the UnitTM Large Demonstration Set you can easily make molecular molecules that the whole class can see. The system uses large 44mm diameter spheres in seven colours to represent different atoms plus a 25mm diameter white sphere to represent a hydrogen atom. Sturdy pegs join atoms and rigid aluminium or flexible vinyl tubes (for double bonding) at any bond angle. A full range of supplementary atoms, bonds and orbitals are available. Set contains: 70 atoms, 144 pegs, 90 bonds. UnitTM.