Best RS232 Serial Adapter Cable to Bare End, DB25, Shielded, Molded Plug (Male) or Plug (Female) with Bare Wires, 1.5m, 3.5m, 7.6m Length; Each cable is a separate color for easy identification and they are labeled with the pin they are connected to. Those with DB9, DB15, and DB25 connections are RS-232, so they transmit data between computers and equipment. The knurled screws on these connectors have slots so they can be tightened with a screwdriver in tight spaces.