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.