So why only 4 stars? - Well, one of our three built into the house's UniFi UAP AC's making sounds during transmission. - Sounds? An access point? - No, not a typo. I suspect that it is due to a built-up switching elements (Elko?). If the AP is under load, then it is actually quiet, chirping sounds. Who do not believe me - I've got it on video. The functionality is not be affected and really very good.