This pack contains 10x 14W 55cm T5 HE Fluorescent Tubes with Double-Sided Power. These 14W 550mm T5 HE Fluorescent Tubes with Double-Sided Power allow us to maintain fluorescent technology in our luminaires with a boost in quality that only a prestigious brand like Philips can provide. The diameter of the tube is Ø16 mm and the 'HE' that can be seen means: 'High Efficiency'. Also known as triphosphor tubes, these are widely used in kitchens, commercial centres and in any domestic or commercial space. These are areas that require that lights be left on during long periods of time.  These are made from high quality materials, use efficient phosphorous that provide 10% savings when compared with older fluorescent tubes. The installation requires an external feeding that provides voltage until the lights start-up. These Philips tubes also feature a translucent finish that minimizes glare and improves visual comfort. Philips Warranty Policy, Terms and Conditions