Feature:1. Mature and Stable Module: This module supports I/O port as well as UART program download port all pinout, programmable keys and reset keys, mature and stable.2. Safe and Harmless: The dual relay board is equipped with WiFi and BLE modules, which are harmless to human body and provide security to the operator.3. Output Switching Signal: This relay board contains 2 way 5V relay with output switching signal, suitable for controlling loads with operating voltage of AC250V or DC30V or less.4. Large Capacity: This dual relay module has a large enough capacity of 4M, you can use it with the actual situation.5. Applicable Scenario: This dual relay module is suitable for secondary development learning, smart home, wireless control, etc. If you have related needs then this one is suitable for you.Specification:Item Type: Dual Relay ModuleMaterial: PCB Copper BoardProduct Voltage: DC5-60V.Package List:1 x Module2 x Double Row 10 PIN1 x Double Row 6 PIN1 x Single Wire CoverNote:Pay attention to correct operation.