Tom tilted his head. "Yes and no. While it can be used that way, that is not the main purpose." With a spell, he opened the sealed compartment. "This is floo powder. If you put correspondence in the big drawer and sprinkle floo-powder over it, it will send the items, letters, scrolls to the address you specify. I have a similar box that can be reached by using >Marvolo Riddle<."