The Dwyer Instruments DS-400-24-LV is a low voltage, 24 VDC, 4-20 mA output differential pressure switch. It is designed for use in applications where a low voltage power supply is required, such as in battery-powered or solar-powered systems. The DS-400-24-LV is also suitable for use in applications where a 4-20 mA output signal is required, such as in process control systems.