Zilla Night Black Heat Incandescent Spot Bulb, 100-Watt (3 Pack) Pack of Three Zilla Night Black Heat Incandescent Spot Bulb, 100-Watt Emits a focused, 24-hour heat source ideal for reptile basking areas Great for night-time viewing to observe natural nocturnal behaviors Ideal for tropical and desert habitats Made from glass containing rare earth black phosphors