4 Port Professional RS-232 USB 2.0 to Serial Adapter
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4-Port USB to RS-232 Serial Adapter Hub
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USB to 4 Port RS-232 Serial Converter, 4x DB9 Male - Lindy Australia
4 Port USB to DB9 RS232 Serial Adapter - Serial Cards & Adapters | StarTech.com
LINDY USB to Serial Adapter - 4 Port (9 Way, RS-232) : Amazon.co.uk: Computers & Accessories
Large Selection of USB-RS232 adapters, Easy Installation and Setup of USB RS232 COM ports.
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4-Port USB to RS-232 Serial DB9 Adapter Cable w/ FTDI Chip
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