Mini breadboards are used mainly to construct small optical experimental setups. The thickness of mini breadboard is 5mm. There are M4 tapped holes on 12.5mm grid.
Standard Solid Breadboards are commonly used platforms for building optical setups. It’s thickness is 10mm. There are M6 tapped holes on 25mm grid.
Heavy duty breadboards are available in 18mm thickness. These breadboards are heavy and can be used for building rigid setups.