Features Knob operation, adjust output response fast, no delay. The power port has polarity protection and will not damage components when the power is reversed. Can be used for signal source, valve regulation, output meter test, LED test, analog transmitter. To test whether the output is normal, you can use a multimeter to short the "4-20mA output" terminal. Easy to use and convenient to connect wire with good performance. Specification:Item Type:Current Signal Generator Power Supply: DC 12V or 24V Current: 4-20mA Total Power: <1W Output Load Impedance: 0-350 Ohms (DC12V); 0-800 Ohms (DC 24V) PCB Board Size: 50 x 50mm / 1.97 x 1.97in Package List:1 x 4~20mA Signal Generator Module1 x Users Manual English Package List 1 x 4~20mA Signal Generator Module 1 x Users Manual English