①Semi-vortex impeller permits foreign matter passing sized 40 to 63% of discharge diameter.②Hydraulic design is optimized raw sewage transfer application for small domestic wastewater treatment plant.③Built-in motor protector protects the motor from overload or open phase.④Optional quick discharge connector facilitates easy installation and maintenance.⑤DVSA model permits automatic operation. Parallel alternate operation possible with DVSA and DVSJ model.