Zoo Med 2 Pack of PowerSun UV Reptile Bulbs, 100 Watts, Self-Ballasted Mercury Vapor UVB Lamp. This self-ballasted lamp is crafted to emit UVA, UVB and heat all in one convenient lamp. UVB radiation helps promote healthy calcium absorption, which can help prevent metabolic bone disease in reptiles. Claw-fect for large terrariums and bird aviaries, it projects UVB up to several feet from the lamp's surface. This mercury vapor bulb is designed to fit in a standard ceramic socket for your convenience and features nickel-plated threads to help prevent corrosion.