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CFL (compact florescent light) Spiral Light Bulb

Compact florescent bulbs are no-brainers. Compared to standard incandescent bulbs, CFLs reduce lighting costs by about 70%, operate at a much cooler temperature, last about 5 times longer and, of course, cost more. But they're worth it because the operating cost is much less and you change them less often. CFLs are especially useful for ceiling fixtures that are a pain to access or common hallways where lights are on for long periods of time.

CFL Spiral Light Bulb