Grid luminaire, luminaire, ceiling light, Grid luminaire, Design lamp 2x54W with Doppelparabolraster (BAP) and electronic ballast
With Osram lamps (will not advertise) radiates the light real supper, "hum" is the power supply really do not you listen to it in any case, it does not bother me because I always tranquility when tinkering wake've :-), so a star Weck.