T4 fluorescent tubes. T4 tubes have a diameter of 12mm and are most often used in under cabinet lighting and emergency exit lights.
There is a variety of wattages and lengths of T4 tube available, but the wattage is does not necessarily dictate the length of the tube, so make sure that you know what size of tube you need as well as the wattage.
T5 fluorescent tubes. T5 tubes have a diameter of 16mm and are often used in ceiling, under cabinet lighting or emergency lighting. They are also often used as the light source in illuminated bathroom mirrors and cabinets.
T5 tubes are more efficient than T8 tubes, and are often used instead of the larger T8 tubes in commercial and retail and office lighting.
There is a variety of wattages and lengths available, but the wattage is does not necessarily dictate the length of the tube, so make sure that you know what size of tube you need as well as the wattage.
T8 fluorescent tubes. T8 tubes have a diameter of 25mm (or one inch) and are often used in ceiling fittings and some under-cabinet lighting. They have been the most common source of fluorescent lighting for many years.
They are available in a range of sizes and wattages and colour temperatures from warm white, to daylight white.
Unlike T4 and T5 tubes, the length of a T8 can usually be determined by it's wattage.