Features: brand new and high quality Output Ttl level can be detected with the microcontroller. The power supply can be 3-5V Can also access PLC24V level Then the Plc input terminal of the Plc COM power supply 24V input termination of the board signal output OUT, optocoupler board GND power negative Blue 2P 5.0 terminal connected to 220V voltage 3Pin terminal connected to the microcontroller input. Specifications: Board Size:approx 73x15mm/2.87x0.59in Functuon:Testing whether AC 220V is existed Ouput Ttl Level: Can use Scm to test Voltage: 3-5V Adaptive to PLC24V level Note: When the power module in the power of the board after the white wire frame can not for touch any device .. because it is high voltage. Note the safety of electricity. Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment. Package includes: 1 x 1Channel AC 220V Optocoupler Isolation Module