CAT 6 Flat Patch Cord 3m White The flat Ethernet cable is a flat form of copper wire with the twisted pairs arranged side by side rather than squared up. Most flat Ethernet cables are unshielded because it is very difficult to place an overall shield on a flat Ethernet cable, as the shielding material tends to become round which cannot hold a flat format. This makes external EMI (Electromagnetic Interference) protection of the flat Ethernet cable not readily available, because this natural shielding tendency provides better protection against external EMI for round cables. http://www.fiber-optic-equipment.com/flat-ethernet-cable-vs-round-ethernet-cable.html