Features: 1High level trigger means that there is a positive voltage between the signal trigger terminal (CH) and the negative pole of the power supply. 2High?level triggering is a triggering method in which the positive pole of the power supply is connected to the trigger terminal. When the trigger terminal has a positive voltage or reaches the trigger voltage, the relay will pull in. 3Low? level trigger refers to when the voltage between the signal trigger terminal and the negative pole of the power supply is 0V, or the voltage at the trigger terminal is lower than the voltage of the positive pole of the power supply, when the voltage is low enough to trigger, the relay pull in. 4Low?level trigger is usually a trigger method that connects the negative pole of the power supply to the trigger terminal, so that the relay pull in. 5The input terminal can only be connected to DC power, and the output terminal can only be connected to AC power (the output terminal cannot be connected to DC power). The maximum operating current is 2A. Package included: 1 x Relay Module