Viking Quick Response Extra-Large Orifice Pendent Sprinkler VK377 (storage/density/area) is a thermosensitive glass bulb spray sprinkler available in several different finishes and temperature ratings to meet design requirements. The extra-large orifice provides greater flows at lower pressures than standard orifice or large orifice sprinklers. This feature allows reduced pipe sizing for hydraulically calculated sprinkler systems, which require high densities of water.