NulSom Inc. Ultra Compact RS232 to TTL Converter with Female DB9 and Hood Kit (3.3V to 5V)

This adapter helps to convert TTL (Transistor-Transistor Logic) level signals to RS232 interface. This converter has a Female DB9 connector (NS-RS232-01: B00OPTOKI0) and a plastic Hood Kit.
Suitable for use with most microcontrollers, 300 to 115,200 bps (up to 230,400 bps).
Compatible with Arduino, Raspberry Pi, and any micro controller, such as PIC, Atmel, STM or other system with TTL serial communications.
Operate with 3V to 5.5V power supply. You can use this on both your 3.3V and 5V projects.
Perfect for any RS232 to TTL electronic projects.
http://www.nulsom.com/datasheet/NS-RS232_en.pdf

RTS (Board) > T2IN (SP3232EEY) T2OUT > Pin 8 (Female DB-9 connector)
CTS (Board) < R2OUT (SP3232EEY) R2IN < Pin 7 (Female DB-9 connector)