Feit Electric's 13 watt Equivalent Direct Replacement (Type A) Non Dimmable Linear LED Tube replaces F13T5 or T5 fluorescent and LED tubes. They work with most existing electronic ballasts for quick and easy plug-and-play installation, with no rewiring necessary. Each Linear LED light produces 1100 lumens, while using less energy than fluorescents. These versatile 4000K Cool White lights provide clean, mid-range light for both living and workspaces. Use them for multi-purpose lighting or task lighting wherever it is important to feel refreshed and ready to get things done. An ideal choice for most fluorescent linear tube replacement applications, use them in offices, garages, workspaces, warehouses, and more. T521/840/LED lights turn on instantly, offering flicker-free full illumination with no warmup time compared to fluorescent tubes. They are mercury-free, with a shatter-resistant coating for safe and easy disposal. Each high-quality bulb offers accurate color-rendering, for more vibrant, true-to-life colors. Lower heat emission extends the life of the tube and ends do not turn black or burn with age. The estimated energy cost is only $1.45 per year. Switch to Type A LED linear lights for your space and get up to 35,000 hours of superior light. That's 31.9 years based on 3 hours of daily use.