The BER series aerators combine B series submersible pumps with venturi-jet based diffusers. They draw in air from above the wastewater by generating negative pressure around the nozzle with the flow from the pump. The air is mixed into the wastewater by this jet injector mechanism and sprayed underwater by the diffuser, to aerate and agitate the wastewater at the same time. In the process, tiny bubbles form inside the diffuser and increase the amount of dissolved oxygen in the wastewater. The powerful unidirectional jet that results can efficiently agitate long narrow tanks, as well as wider areas when multiple units are used. BER is capable of anaerobic agitation. Each model is available as a free-standing unit or with an auto-coupling set (TOS) for guide rail use.