Our simplex indoor 18'' x 30'' polyethylene basin is an essential component to the pump system. It collects water or wastewater through a 4'' inlet (4'' pipe seal included). The pump will evacuate the liquid when called to turn on through a switch (not included). This basin includes a steel cover with an opening for a 2'' vent, 2'' discharge and cord opening. The 2'' pipe seals, cord grommet and cover seal, when properly installed, allow the cover to be gas-tight to prevent odors from escaping the basin into the indoor atmosphere. This basin can be used indoors in a residential or light commercial building using a submersible effluent or sewage pump.