Night Red Heat Incandescent Bulbs Provides 24-hour ambient heat source for a healthy reptile environment Red light provides nocturnal viewing without disturbing the reptiles day/night cycles Ideal for tropical and desert habitats; the bulb provides ambient heat in which most of the photons emitted by the filament never escape the dark tint heating the air inside the enclosure to create the warmth needed for a healthy reptile environment. The bulb is made from glass containing rare earth red phosphors and emits red light which is less visible to reptiles great for nocturnal viewing without disturbing the reptiles day/night cycle. This Product/Package Measures: 3.25 in. L x3.25 in W x5.50 in D br/>Sold in Quantity of: 1