This philips hf r td 124 tl5pl l dimmable ballast runs between 1 x 24w t5 fluorescent tubes and 1 x 24w pl l this ballasts lamp power can be regulated from 1 to 100 automatic stop start automatic restart after lamp replacement up to 75 reduction in energy consumption and quick programme flicker free startthe philips hd f ballasts are commonly used in offices these units are for use with installations with emergency back up