Adventurer's Lantern

You have found an old, brass lantern that has three separate windows that are operated mechanically by unlatching and opening a small, rectangular door.  Hanging within the lantern is a crystal that gives off eternal light. Opening the "front" door will will reveal the bright light within, throwing out a cone of light that will be brightly lit out to 20 feet, and dimly lit an additional 20 feet. Opening the side windows reveals cones of light that are bright 10 feet out, and dimly an additional 10 feet. 

Subjecting the lantern to any kind of effect where magic is dispelled will only suppress the light for 30 minutes.