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 Cap/Base 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 fitting, it must be replaced with an 55w lamp. You cannot reduce or increase the wattage.