Adapt an existing DB9 M/M cable With DB9 cables from Cables To Go, you will no longer sacrifice convenience when it comes to the placement of computer peripherals in your work area! Let us give you the flexibility to add an existing piece of hardware wherever you need it. Our DB9 extension cables can convert your existing connections or replace the cables that restrict you. Each extension cable comes fully shielded to prevent against unwanted EMI/RFI interference, and its fully-molded design delivers excellent strain relief.