6 Pack F15T8/CW 18 Inch 15W T8 Fluorescent Tube Bulb Cool White 4100K Medium About this item KINDLY NOTE: THE DEFECTIVE BALLAST IN FIXTURE WILL CAUSE THE BULB FAILED TO WORK. When the lamp is not powered on, the mercury inside the tube is in liquid form and will produce a collision sound when shaken. Features: Wattage: 15W; Length: 18 inch/1.5 Feet; Base: Medium Bi-Pin G13; Color temperature: 4100K; CRI: 80+ Long-Lasting and Reliable: This 15W Fluorescent lamp has a lifespan of more than 12000 hours, more than seven times longer than an average incandescent bulb! Excellent Performance: The Product comes with a Color Rendering Index(CRI) of 80+ which is crisp and comfortable for the eyes, illuminates your space with crisp and comfortable day light. Easy to Install: Designed as a universal replacement fluorescent bulb, this T8 tube comes with a G13 base which is a very common base. Enjoy the hassle-free installation. After-Sales Service: We provide a 180-Day warranty for the bulb. If there is any problem during the warranty period, please feel free to contact us.