This Philips HF-R TD 424 TL5/PL-L dimmable ballast runs between 4 x 24w T5 fluorescent tubes and 4 x 24w PL-L. This ballast's 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 program flicker-free start. The Philips HD-f ballasts are commonly used in offices. These units are for use with installations with emergency backup. Philips Product Number: 871150091374630