Chocobo Saddlebag
The Chocobo Saddlebag is an additional storage location unlocked by the quest 
My Feisty Little Chocobo. It can be opened under the the Character menu, or by pressing the hotkey Ctrl+Shift+I. The saddlebag contains 70 slots for items.
A second tab with an additional 70 slots (called the "Right Saddlebag") is included with the FINAL FANTASY XIV Companion App's Premium Service Plan (5USD/month).
Saddlebags cannot be opened in instanced areas, such as duties and 
Field Operations zones.
Saddlebags are treated as separate from the player's main inventory, similar to Retainer inventories. This is notable for items that are tagged UNIQUE, as the player can store one copy in the saddlebag and one copy in their main inventory. This trick is especially useful for items such as Treasure Maps and 
Proof of Covering.
- However, the two saddlebag tabs are considered part of the same inventory, so it is not possible to store one unique item in the left bag and one in the right bag.