Positive 5V: + 5V positive power supply, input or output GND: power ground, input or output P30 - P35: CH3 - CH8 control lines, high level effective. : short and to the module power settings to the factory settings Blue Terminals: Connect load, you can use 220V AC, or less than 30V DC equipment, which can not the current standard load relay. Each relay has a normally open contact, a normally closed contact and a common contact, relay , public contact and normally open contact conduction; relay released, public contact and normally closed contact guide pass.AH893 Material: plastic, metal color: red Size: 70X 50mm Package Included: 1x LAN Ethernet 2-way Delay Time Switch Relay Board /UDP Controller Module