This 55w t5 circular lamp has an average life of 12 000 hours and has a b class energy efficiency rating the colour temperature is 4000 kelvin cool white box quantity 30 general characteristics wattage w 55 voltage v 230 lumens lm 4200 capbase 2gx13 bulb shape circular bulb diameter mm 293mm colour rendering index cri ra 82 rated life l7 h 12000 dimming capability yes please note these lamps should be replaced like for like if you have an 55w lamp in your fi