BPN/O model monitor nozzles use hydraulic actuators to adjust the discharge pattern of the nozzles. BPN/O model nozzles are used in combination with MMO model hydraulic operated monitors. At a constant pressure, the ﬂow rate remains the same, but the discharge geometry varies from jet to fog. In case of hydraulic pressure failure, a hand lever is provided for manual operation. C.S.I. S.r.l. produces hydraulic driven selectable discharge pattern nozzles with up to 30.000 l/min ﬂow rate.