A white plastic disc (with a blue center) Flow Control Disc Emitter which when inserted into a female hose connector, allows a 1.0 gal/hr flow rate into a header hose regardless of the upstream water pressure. The minimum upstream water pressure required is 10 psi and therefore it cannot be used with a gravity tank installation. The maximum upstream water pressure is 70 psi. The blue side must face the upstream water flow when inserted into the Female Hose Connector.