Amazon.com: ELECABLE USB Type C to RS232 DB9 Serial(9-Pin) Converter Adapter Cable 5ft with a Male to Female Connector, Compatible with MAC OS, Windows, Android, Linux Type C Device (USB C) :
USB Type-C - RS232Cコンバータ USB-CVRS9HCの通販ならサンワダイレクト
What is RS232 Serial Communication Protocol? RS232 Basics, Working & Specifications
USB Type C to Serial Cable DB9 RS232 - rhinocables.co.uk