Abstract: A dripper unit comprising a base section and a perforated cap attached thereto; the base section for attaching to an irrigation pipe through which water flows, and having a conduit of a first diameter therein, such that some of the water flowing through the pipe flows into the conduit within the base section; the cap for regulating water flow out from the dripper unit, wherein the cap is characterized by having a plurality of apertures there through, each aperture having a different throughput, such that rotation of the perforated cap with respect to the base section brings a selected aperture from said plurality of apertures into alignment with the conduit, thereby regulating flow out of the dripper unit.