This is felt wizards hat, grey in colour similar to Gandalf's from the Lord of Rings/The Hobbit films and images.
Apparently, the name Gandalf comes via Tolkien from a Norse mythology name meaning staff man or wand elf.
Gandalf wore the grey hat before he became head of the Middle Earth wizards, while he was the Grey Wanderer, the Grey Pilgrim, Greyhame, Gandalf the Grey, among many other names which don't contain the word grey.
The hat will soon be adopted by a character I play in lrp.
The hat was purchased from Leonardo Carbone.