Lightweight, slim Dimmable High Frequency HE Ballast for controlling Single 28 Watt T5 Fluorescent Lamps. Benefiting from flicker free operation and smooth warm lamp start, alongside protection against over voltage and incorrect connection it is a trusted and reliable unit that also offers a 50,000 hour service life. Offering a 60% reduction in energy consumption compared to a conventional ballast this is a popular choice in offices, supermarkets, public buildings and educational establishments this measures just 21mm x 360mm x 30mm (h x l x w).