Interference Resistance: The relay module features optocoupler isolation for high interference resistance, along with Bluetooth status and relay indicator lights. Two Interfaces: The module includes a UART debugging interface with a baud rate of 9600 and an MCU program interface, supporting further configuration and operation. Current Drainage Protection: This 4-channel relay is rated for up to 100,000 continuous cycles, equipped with diode current drainage protection and fast response time. Remote Control: Integrated with a Bluetooth module supporting SPP protocol, enabling control distance of up to 30 meters in open environment. Practical and Safe: Constructed from PCB material with fine craftsmanship, this relay module is safe, reliable, and designed for long-term use. Item Type: 4 Channel Bluetooth Relay Module Material: PCB Control Distance: 30M (open environment) Protection Characteristics: Epoxy resin Contact Load: Low power consumption Package: 1 x Relay Module