Features: 1.Standard for Raspberry Pi 40PIN GPIO extension, support for Raspberry Pi series board. 2.Adopts SC16IS752+SP3485 dual chip combination, converts for SPI to RS485, data rate up to 921600bps 3.Allows transceiving data manually or automatically, configured by DIP switch. 4.Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, anti?electrostatic. 5.Onboard auto?recovery fuse and protection diodes, ensures the current/voltage stable outputs, provides over?current/over?voltage proof, improves shock resistance 6.Onboard LEDs for indicating the power and transceiver status. 7.Break through for SPI control pins, for connecting with host control boards. specification:Condition: 100% Brand New Item Type: RS485 Expansion Board Material: PCB Applicable: for Raspberry Pi 3B 4B 2?Channel Isolated Size: As Pictures Show PackageList: 1 x RS485 Expansion Board 1 x Pin 1 x Bag of Accessory