Teradek Node Celluar 3G/4G/LTE 4-Pin to USB Modem (US) 10-0020
Null modem cable
Amazon.com: USB to RS-232 DB9 Female 9 Pin Null Modem Rollover Serial Adapter Cable for Windows,Linux MAC OS (Null Modem) : Electronics
Amazon.com: StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable F/M - DB9 Male to Female - 9 pin Null Modem Cable - 1x DB9 (M), 1x DB9 (F), Black (SCNM9FM2MBK) : Electronics
C2G DB9 Male to DB9 Female Null Modem Adapter - 1 Pack - 1 x 9-pin DB-9 RS-232 Serial Male - 1 x 9-pin DB-9 RS-232 Serial Female - Beige - Office Supply Hut
StarTech.com USB to Serial Adapter - Null Modem - FTDI USB UART Chip - DB9 (9-pin) - USB to RS232 Adapter - PCC-IT International
13657: Null Modem Cable, 9-Pin Socket (Female) to 9-Pin Socket...