An expensive part.
This little bulb goes to the Noritsu LP-2200 printer at my work. This thing costs real close to $200. OUCH! The inside filament is pretty neat. Looks like a crystal cave.
Strobist info: AB800 @ full power, fired into a white w/ black backing umbrella. Canon 20D on tripod, Canon 100mm Macro lens, ASA 800, 1/250 @ f/8 Triggered with Pocket Wizards.