Attach virtually any existing external modem with a DB25 female serial port to the serial DB9 port on your computer. Featuring oversized ergonomic thumbscrews for easy installation, the AT Serial Modem Cable from Belkin features a state-of-the-art wiring design including copper conductors insulated in polypropylene to minimize cross talk and provide high-speed, error-free transmissions. The generous 100-foot length assures you will have no problem reaching your computer connection, and the PVC premolding ensures electrical isolation and stress relief.