The PowerSun ¨ UV is a self-ballasted mercury vapor lamp which emits UVA, UVB, and heat all in one lamp! Fits into a standard ceramic socket (No ballast needed). The 160 Watt projects UVB up to several feet from the lamps surface and is ideal for large terrariums or bird aviaries. Quality nickel-plated threads to prevent corrosion. These lamps need specific line voltages; they cannot be used with dimmers/rheostats.