This module can be used to test the current and voltage. The principle of voltage test based on principle of resistive voltage divider design, can make the red terminal connector input voltage to 5 times smaller. Analog input voltages up to 5 v,the voltage detection module input voltage not 5Vx5 = 25V (if using 3.3V systems, input voltage not 3.3Vx5 = 16.5V) AVR chips have 10-bit AD, so this module simulates a resolution of 0.00489V (5V / 1023), so the minimum voltage of input voltage detection module is 0.00489 Vx5 =0.02445V. The MAX471 chip on the board used to test the consume current of the load.<br><br>Size:19.5x20.3mm Test Voltage range:DC3 - 25V (Ard work on 5V) or DC3 - 16.5V (work on 3.3V) Test Current range:DC 0-3A Colour:As Shown Material:PCB<br><br>Package Contents: 10 * Sensor Module<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.