... highfrequency above 20KHz,no noise,it couldprotect our eyesight effectually with nofrequency twinkling and soft ray.5.Small cubage,it ... installed in anylighting convenienlty which should be matchwith T8/T4 lamp.Application:Hotels, chain restaurants,office buildings, museums, stadiums,exhibition ... in T8/T5/PLL electronic ballast from 8w-58w,with a lamp,two lamps,three lamps and four lamps.(We also ...