One of the most popular and widely used lighting options available, fluorescent tubes come in several styles and shapes, but they all produce light using the same process. Electric current passes through a mercury-vapor and excites the gas. This produces ultraviolet light that then causes a coating on the inside of the fluorescent bulb to glow. 1000Bulbs.com offers a variety of fluorescent tubes, including circline, U-tube and linear tubes. We also offer T5 and T8 tubes. The "T" in the name of this tube stands for "tubular," while the number indicates the product's diameter. T5 tubes have a diameter, or "thickness," of five eighths of an inch, and T8 tubes are eight eighths of an inch (one inch) thick. We have the expertise and the selection to help you find the perfect fluorescent tubes no matter your needs.