This philips hf r td 139 tl5 dimmable ballast runs between 1 x 39 watt t5 this ballasts lamp power can be regulated from 1 to 100 digital control input according to the industry standard dali digital addressable lighting interface combined with the touch and dim pushbutton protocol 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