Outputting 80 lumens per watt this 18W V-Tac slim square LED panel will save up to 80% energy usage over a traditional incandescent panel. This model will emit a cool white colour temperature of 4000K and will provide instant bright light at start up over a 20000 hour life. Product Dimensions are Height 190mm x Width 190mm x Depth 24mm. Please note that the true colour output of lighting products should be based only on the Kelvin rating. The descriptors warm white cool white daylight etc are used only as guides to describe the colour of the light and can vary between brands.