Yes, it is clickable from inventory - for questions like this I suggest visiting Lucy as that site also lists the requirements for clickies. And for this item it says :
Quote:
(Any Slot/Can Equip, Casting Time: 1.0)
Which means you can click it from inventory as long as you are a wizard and iirc that's what Aridian said as well - i think he uses it as an inventory clickie as he's got an important focus in range atm...