1、DISPLAY CALIBRATION: There are current and voltage display calibration potentiometers on the back of the module. If the display is not accurate, you can calibrate the current voltage display value yourself. 2、PREMIUM CHIPS: Excellent chips are used for signal stability, high reliability, and stable normal operation. 3、WIDELY USED: Our signal adapter can be used as a signal generator, valve adjustment, variable frequency control, PLC debugging, panel debugging, LED testing, and analog transmitter output. 4、EASY TO USE: Comes with a compact size, the signal generator is easy to use. And the knob adjustment allows easy operation, not easy to accidentally touch. 5、DISPLAY METHODS: 2 wire signal generator has 3 display methods, actual current, percentage, Hz. Easy to read and improve work efficiency! 1 x Signal Generator  1 x Manual  Item Type: Signal GeneratorMaterial: ABS Product Overview: 4-20mA signal generator, button adjustment, not easy to accidentally touchPower Supply Voltage: 15v-30vOutput Range: 4-20mA, 3-21MADisplay Method: Actual current, percentage, HzSampling Resistance: Less than 500 ΩOutput Accuracy: ± 0.5%Display Accuracy: 0.01