ITEM NAME:RS232 To TTL Converter Module Serial Module DB9 Connector 3.3V-5.5V Arduino Z.1 MAX3232 RS232 to TTL Serial Port Converter Module DB9 Connector. Port: TX RX VCC GND. It can be used to program STC MCU, NXP MCU, Renesas MCU,STM32 MCU, N+-2EC MCU. Size : 30mmx28mm.