The philips hf m red 124 sh tltl5pl l is a square non dimmable high frequency ballast to run1 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