This nozzle holder from the manufacturer TeeJet is made of high-strenght Nylon and it has a diaphragm back pressure valve which is incorporated in the nozzle holder. The diaphragm closes the outlet at 0,7 bar and the unit is pressure stable up to 9 bar. The max flow rate per minute is 9,5 l. The nozzle holder has a 11/16" thread. For the pipe connection you can choose two different thread sizes.