The second I installed my Bilboa in my vanity it emitted a nasty hum, 120Hz to be exact. After a bit of research, I suspected the ballast, and after some convincing, ATG rep had the mfgr. send me a replacement ballast by a different maker. I performed the transplant and the patient was happy...No buzzing! I was happy too, finally liberated from that noise every time I walked in my bath. Other tips: Ensure a 6-8" clearance from the top of unit to your ceiling for screwing top in. Also, the necessary bulbs (F25T8, I think) are not common, I had to order mine online.

A little less light than i need would be better in lower ceiling bathroom