Features: 1. Protective: The power port has polarity protection and will not damage components when the power is reversed. 2. Fast: Knob operation, adjust output response fast, no delay. 3. How to test: To test whether the output is normal, you can use a multi-meter to short the "4-20mA output" terminal. 4. Convenient: Easy to use and convenient to connect wire with good performance. 5. Application: It can be used for signal source, valve regulation, output meter test, LED test, analog transmitter. Specifications: Material: PCB, chip, digital tube Color: Dar green Size: (Approx)(LxW)50 * 50mm/1.97 * 1.97inch Power supply: DC 12V or 24V Current: 4-20mA Rate: <1W Output load impedance: 0-350 ohms (DC12V); 0-800 ohms (DC 24V) Package Included: 1 x Signal Generator Module Note: 1. Due to the light and screen difference, the items color may be slightly different from the pictures. 2. Please allow 0.5-2 cm differences due to manual measurement.