Ideal for tropical and desert habitats the bulb provides focused heat while the photons emitted by the filament never escape the dark tint. The spot bulb provides a focused beam of energy to heat the air inside the enclosure to create the warmth needed for a healthy reptile environment. The bulb is made from glass containing rare earth black phosphors, which simulates the moon's natural glow for nocturnal viewing without disturbing the reptile's day/night cycle.