8W F8T5 fluorescent lamp, T5 fluorescent tubes,fluorescent lighting,8watts,High Output fluorescent tube. Ideal for use in offices with high ceilings and for applications where a high lumous flux is required. For use with electronic control gear only,T5 lighting is a relatively new light source in the United States that was originally developed as a light source in combination with specialized reflectors for aquarium lighting. T5 & T5HO (High Output) lamps, The smaller diameter 40% smaller in diameter than T8 Lamps, Economy of scale, however, is not the complete story. The small diameter of the lamps (5/8") together with the use of high performance reflectors, results in more precise control of the direction and the output of the light source.