The Viking Mirage® Model VK636 Quick Response Extended Coverage Light Hazard ELO Concealed Pendent Sprinkler is designed for installation on concealed pipe systems where the appearance of a smooth ceiling is desired. The sprinkler is designed with an extra-large orifice and a special deflector to meet Light Hazard density requirements for specifically listed extended areas of coverage at lower pressures than standard or large orifice sprinklers.  See technical datasheet for required design and installation criteria.