The base fits most standard sockets. Perfect for reading, crafting, studying and more, OttLite lighting delivers the right mix of brightness and contrast so you can see colors accurately and fine print and details with ease. And, this unique low heat, low glare illumination that helps reduce eyestrain. This replacement light bulb is designed to fit into most standard light sockets. This makes it easy and convenient for you to choose OttLite lights with confidence and have easier installation. Details: Replaces 100-watt incandescent bulbs Replacement bulb type V Fits most standard light sockets True colors, clear details and reduced eyestrain Low heat and low glare illumination Energy efficient Rated to last up to 10,000 hours