(Pack of 4) 13 Watt Single Tube - Gx23 (2 Pin) Base - 4100K Cool White - CFL Light Bulb. GX23 Base: Plug-in CFL sockets are designed to only work with one style of pin base to ensure the correct light bulb is used to match the ballast in the fixture. So make sure that the base (Gx23) matches exactly to your fixture socket as this will only work with this specific base number and will not interchange with other base/socket numbers. Color Temperature 4100K: This 41K cool white color temperature is cool and gives out a cool clean look and works well for ambience lighting in kitchens, bathrooms. It is perfect throughout your home and can be used in your desk/table lamps, floor lamps, and open pendant fixtures. Long Life: This 13W compact fluorescent bulb offers a long life compared to a regular 60-Watt incandescent bulb which makes it a maintenance free option to light your house or any lighting application. Dimension: Overall length 7” These 2-pin CFL bulbs are designed to be an exact replacement for major brand. They are made with great care and quality at a fraction of the cost of the major brands while not compromising the quality or the lifespan of the bulbs.