Grex Airbrush Quick-Fit Crown Cap. The Grex Airbrush Quick-Fit Crown Cap is intended for use on the Grex Genesis.XGi, XSi, XBi, and the Tritium.TG and TS airbrushes. The Quick-Fit Crown Cap is designed to protect the needle and nozzle of the airbrush while still allowing optimal airflow and paint atomization. The Crown Cap helps control the spray pattern, reducing overspray and allowing for more precise application, which is especially useful for detailed work. The quick-fit design allows for fast and easy attachment and removal of the Crown Cap without the need for tools. This streamlines the workflow and reduces downtime, allowing the artist to focus more on their projects.