Features: -With relay output, this module is used to detect the humidity and control related the device power directly. -This product make use of HR202 humidity sensor. -The comparator outputs drive relays directly. It connects to 220V AC or other devices. -With leads, sensor interface can be installed with pin. -It's easy to install with 4 0.3cm fixing bolt hole. -When ambient humidity exceeds the setting threshold value the relay sucks and shuts, what's more, the common terminal connects to the start. -If the ambient humidity below the setting threshold value, the situation will be counter. -Common, normally open and normally closed the three ports are equivalent to a dual-control switch. -When the relay coil is electrified, the common will connect to the normally open, otherwise, the common will connect to normally closed.