The Fluid Nozzle and Needle MUST always match exactly. The sizes , and setups are ideal for all fine finishing. There are a total of 7 different aircap sizes are available. Generally speaking, the quality of atomization and finish suffers as you go to the largest size setups ( and ). Please note that the chart offers you a starting point only as to the setup size to be used. The best way to decide is by experimentation. If you are using the standard setup and wish to spray faster and wetter, then switch to larger aircap set.