Standard Raspberry Pi 40PIN GPIO extension header, supports Raspberry Pi series boards ^^ Adopts SC16IS752+SP3232 dual chip combination, converts SPI to RS232, data rate up to 921600bps ^^ Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic ^^ Onboard LEDs for indicating the power and transceiver status. Breakout SPI control pins, for connecting with host control boards like Arduino ^^ Comes with development resources and manual (examples in C and Python)