StarTech 1-Port USB to Null Modem RS232 DB9 Serial ICUSB232FTN
USB to Null Modem Serial DCE Adapter - Serial Cards & Adapters | StarTech.com
C2G 75ft Serial RS232 DB9 Cable with Low Profile Connectors F/F - In-Wall CMG-Rated | Camcor
Amazon.com: CableCreation USB to RS232 Serial Adapter (FTDI Chip), 6.6 Feet USB to DB9 Female Converter Cable for Windows 10, 8.1, 8, 7, Vista, XP, Linux and Mac OS X, macOS, 2 Meters/Black : Electronics