The USB 2.0 Dual Serial Convertors - 80cm - is a USB to Serial RS-232 Cable provides 2 RS-232 Serial (DB-9 male) connectors via one standard USB port. You can instantly enjoy connectivity with your Modem, PDA, POS or other serial devices on your PC or Mac

USB 2.0 Quad Serial Convertors - 80 cm -  is a USB to Serial RS-232 Cable provides 4 RS-232 Serial (DB-9 male) connectors via one standard USB port.

USB to Dual Serial Adaptor provides 2x 9 way RS-232 serial ports which can be used with modems, digital cameras, GPS devices, scanners, PDA��Äôs, serial mice etc.

USB serial converter operates as a connection between one USB port and a 9 way RS232 serial device.

The USB serial converter is for connecting serial devices even when a serial port is not available within a PC or laptop.