discharging plumbing fixtures which for example for design reasons offer little space for accepting the functional unit this way compact functional units can be realized with an overall height of the insertion cartridge including the attachment screen amounting to approximately 1 5 cm advantageously the internal thread of the discharging plumbing fixture has a distance from its mouth smaller than a distance of the housing ring seal from the internal end of the external tread of the housing this way the threaded connection already engages during the assembly of the functional unit before the ring seal enters the discharge plumbing fixture so that in particular a manual assembly process is considerably facilitated on the other hand during the assembly the ring seal can be moved out of the seat in the fixture by rotating the functional unit in the axial direction until it is no longer engaged and before the threaded connection is disengaged this facilitated assembly and disassembly is particularly important because the insertion cartridge is arranged as a u201c hidden inserted cartridge u201d with at least the overwhelming portion of its longitudinal extension preferably its entire longitudinal extension inside the discharging plumbing fixture beneficially the jet fractionating part is provided at the inlet end with an insertion opening for the attachment screen with an external circular wall and a support stop with the holding elements for fastening the attachment screen being embodied as snapping.