DB9pin Female to USB RS232 Null Modem Cable for Two DTE Device Communication Dsub 9pin to USB2.0 NMC - AliExpress
Null modem - Wikipedia
FAQ - Straight Through Serial Cable vs Null Modem — DriverGenius
Black Box Rs232 Shielded Null Modem Cable - Metal Hood, Db9 Female/female, 6-ft. (1.8-m) (EYN257T-0006-FF) | OfficeCrave.com
RS-232 Null modem cable
Null modem - Wikipedia
CableCreation USB to RS232 Adapter with PL2303 Chip 3.3 FT, USB 2.0 to RS232 Female DB9 Serial Converter Cable for Cashier Register, Modem, Scanner, Digital Cameras, CNC, 1M Black - Walmart.com
DB25 Male to DB9 Female Serial RS232 Null Modem Cable
Null modem - Wikipedia
C2G 02520 Serial RS232 Modem Cable DB9 Female to DB25 Male 15' – Maverick Industrial Sales
StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable FM 2m DB9 Null Modem Cable DB9 Male to Female Cable RS232 Null Modem Cable 9 pin Null Modem Cable 2 m Male
StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable FM 2m DB9 Null Modem Cable DB9 Male to Female Cable RS232 Null Modem Cable 9 pin Null Modem Cable 2 m Male