What is the size of Monera?

Monera, a kingdom that includes prokaryotic organisms such as bacteria and archaea, typically ranges in size from about 0.2 to 10 micrometers in diameter. These unicellular organisms can vary widely in shape and form, including spheres (cocci), rods (bacilli), and spirals (spirilla). Due to their small size, they are often only visible under a microscope.