These bags only hold items obtained in the mining profession, but are larger than the average world drop or craftable bag. Only 1 mining bag may fill a slot in a bank at any time.
“Mining bags are special bags first made available in World of Warcraft: The Burning Crusade...Mining bag
“Triple-Reinforced Mining BagItem Level 85Disenchants into:Not disenchantableBinds when...Triple-Reinforced Mining Bag
“Mammoth Mining BagItem Level 75Disenchants into:Not disenchantableBinds when equipped32 Slot...Mammoth Mining Bag
“Reinforced Mining BagItem Level 65Disenchants into:Not disenchantableBinds when equipped28 Slot...Reinforced Mining Bag