The NX003/NX004 Standard/Quick Response Upright are automatic sprinklers of the frangible bulb type. They are “standard/quick response – standard orifice spray sprinkler” intended for use in fire sprinkler systems designed in accordance with the standard installation rules recognized by the applicable listing or Approval agency (eg., UL Listing is based on NFPA 13 requirements).The upright, pendent sprinklers all produce a hemispherical water distribution pattern below the deflector.