A fire extinguisher discharge nozzle is provided and includes sidewalls and a biasing element. The sidewalls define an aperture through which a medium(s) is dischargeable and are adjustable between multiple first and multiple second positions associated with dilated and constricted conditions of the aperture, respectively. The biasing element is configured to bias the sidewalls toward assuming one of the multiple first or multiple second positions. The sidewalls are drivable toward assuming the other one of the multiple first or multiple second positions in opposition to bias applied by the biasing element in accordance with a characteristic of the medium(s).