The RS485 Board (5V) with Extended Fittings - Raspberry Pi RoHS is a Waveshare product that is specially designed to provide an efficient and cost-effective way to connect Raspberry Pi to other devices that employ the RS-485 communication protocol. The board is based on the UART-to-RS485 chip CH341, which provides industry-standard 5V / 9V power supply and the extended fitting form factor, which is compatible with Raspberry Pi boards. The board features four signal pins of the RS485 protocol, namely RTS, TXD, RXD, and GND, with strong anti-interference protection and ability to control up to 32 devices. This connector board is also RoHS certified for environmental protection purposes, making it an ideal solution for a wide range of RS485-related connection needs.