It's hard to find serial cables since
serial ports aren't widely in use. There is still plenty of technology that implements the serial DB-9 connection and it's important to be able to connect to them. This serial to RJ-45 modular adapter allows you to extend your device right over an RJ-45 cable. This lets you choose the size and distance you want while keeping the costs down.
This modular adapter also lets you select the pin-out that best fits your device. You can make a null modem cable or have a straight pass through cable, depending on your needs. An administrator can switch between pass through and null modem by just changing the end adapters and still use the same RJ-45 cable.