C2G 52187 Serial RS232 DB9 Null Modem Cable with Low Profile Connectors M/F, In-Wall CMG-Rated, Black (15 Feet, 4.57 Meters) Provides serial connections where CMG rating is required for in-wall installation Available in lengths up to 75ft Lifetime Warranty Audio/Video installations in educational and commercial settings often require in-wall rated cable, the CMG-rated line was specifically engineered to meet this requirement while overcoming common challenges faced by installers in these environments. The fully molded cable design delivers excellent strain relief, while connector thumbscrews provide a quick and easy connection every time. This cable is fully shielded to prevent unwanted EMI/RFI interference. Specifically designed to support RS-232/Serial communications, Crafted small and flexible enough to be easily hidden out of sight. The transmit and receive signals are crossed to ensure proper data transmission.