Pack of 4 Exo Terra Sun-Glo Basking Spot Lamp, 100-Watt/120-Volt. The Exo Terra Sun-Glo Neodymium Daylight Basking Spot Terrarium Lamp provides broad spectrum daylight for terrariums. Reptiles require appropriate and high quality lighting in order to meet various metabolic needs. In order to accommodate all these needs, multiple light sources need to be combined. The glass sleeve of the bulb has mixed-in Neodymium, a rare earth metal that changes the color balance of the illumination, giving terrarium animals and plants a more natural appearance. The broad spectrum is ideal for plants' photosynthesis and the UVA light contributes to the reptiles' physiological well-being. The Exo Terra Sun-Glo Neodymium Daylight Basking Spot Terrarium Lamp creates a basking area for thermoregulation and also increases the ambient air temperature in the terrarium.