1. Optional 8-channel relays, flexibly adaptable to various scenarios. 2. Built in CH340 chip, Type-C interface for one click program burning. 3. Optocoupler input and output isolation, strong anti-interference, stable operation. 4. Supports Modbus protocol and is compatible with industrial automation systems. 5. RS485 and USART interface integration, strong scalability and easy networking. Power supply: DC 9-24V power supply/TYPE-C power supply;Module: ESP32; Equipped with WIFI and Bluetooth;TYPE-C interface: power supply and burning;EN reset button: Press the reset button; BOOT key: Press and hold the reset key once to enter download mode;Optocoupler input: controllable relay;Serial port chip: Built in CH340 (can burn programs with one click)Built in: RS485 interface; Support Modbus; Color: Blue Material: plastic Package Contents: 1*8-channel Relay Switch Module,1*plastic casing Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.