This is an excellent example of an energy saving light bulb which has been designed to light up faster than other energy saving bulbs reaching more than 60% of its 550 lumen light output within 60 seconds. It has an average life of over 8, 000 hours & benefits from a T2 tube technology to maximise the available light density. It measures 86mm x 33mm & is an 11w E27 bulb. 11w ES/E27 rapid start energy saving light bulb T2 tube technology measuring 86mm x 33mm 550 Lumens 8, 000 hours