A glowbulb is a device from the Age of Legends that emits light. It never needs replacement or recharging. Since the Breaking of the World, the process used to manufacture glowbulbs has been lost, as well as almost all knowledge of their existence in the first place.
Some have survived in stasis boxes, and even three thousand years later still emit some light. Most glowbulbs are possessed by the Forsaken. The ship captain, Bayle Domon, had possession of one until it was taken by Seanchan soldiers and given to High Lord Turak Aladon.