This item is not available in game.
This item was one of two possible quest rewards from Dry Times. Both it and the quest were removed in Cataclysm.
Many players chose this over Finely Woven Cloak because the cloak was not very desirable and only vendored for a few silver. Whereas with this bag, you could loot anywhere between 20s - 50s. Considering the scarcity of gold in classic WoW, this was a no-brainer to the more experienced players.