4100K - Cool White
18 Watt GX24q-2 Base 4100K Cool White Compact Fluorescent (CFL) Plug In Style 4 pin light bulbs are one of the most commonly used energy efficient lamps on the market. This type of compact fluorescent 4-pin requires a separate ballast to operate the lamp which is typically located in the lighting fixture. If you put in a new light bulb and your fixture still doesn't work then your ballast could be out. If you need help with a replacement CFL ballast please contact our customer service department at 800-581-8705.