Relay Module 4M Byte Programmable Keys Dual Relay Module for Learning Secondary Development DC5-60V Function: 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 the human body and ensure the safety of the operator.3. Output switching signal: This relay board includes a 2-way 5V relay with output switching signal, suitable for controlling loads with an 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 in real situation.5. Applicable scenario: This dual relay module is suitable for learning secondary development, smart home, wireless control, etc. If you have related needs, this one is suitable for you. Specification: Item type: dual relay module Material: PCB copper board Product voltage: DC5-60V Package list :1 x Module 2 x Double Row 10 Pins 1 x Double Row 6 Pin 1 x Single Cable Cover Note: Please pay attention to proper operation.