Dimmable from 50% to 110% Super Lumen. Digital ballast offer many advantages over standard metal coil wound ballast units not necessarily more output but a more effective/constant output so your plants can make the most of the light your providing your plants with. The picture which has the waves visable is produced by a standard type ballast and the solid light is produced by the century dimmable unit, the digital light outut is not visable even to a HD camera due to the high frequency of its firing pulses to the lamp, as plants use light to produce energy a more solid constant out put is far superior.