Ranger Cord

Source
This item is a world drop from level 36-45 creatures all over Azeroth. It can be found inside: It can be also found within containers like:
 * - world drop from level 37-46 creatures (0.4% to 0.6% chance)
 * - rewarded from Cuergo's Gold (0.4% to 0.7% chance)
 * - from fishing in Stranglethorn Vale, Tanaris, Azshara and Feralas (0.01% to 0.1% chance).
 * - located in Uldaman.
 * - located in Tanaris.