The 1m DB9 Null Modem Cable features one DB9 male and one DB9 female connector, letting you connect a serial device to a 9-pin serial port, or move files directly from PC-to-PC by means of a serial link. Serial 9 Pin Extension Cables 9 Pin male to female cables. The pin outs are configured directly through thus can be utilized as serial extension cables. C2G Cables to Go Extension Cable Serial extender DB9 M DB9 F 10M molded thumbscrews black 81381 Cables. Designed to give a dependable connection.