The Philips HF-M Blue 124 LH TL/TL5/PL-L is a linear non-dimmable, high frequency ballast to run:1 x 15 watt or 18 watt T8 1 x 18 watt or 24 watt single turn long 1 x 22 watt circular T5 1 x 24 T5 High output. This ballast has flicker free start,Multi lamp ballast, Compact power IC and energy saving of more than 25% compared with electromagnetic gear. The Philips HF-M Blue range is suitable for installations with emergency back up.