Regarding SKU# COM-07950 (Buzzer - PC Mount 12mm 2.048kHz), the description for this product is somewhat confusing. This product is not what I would consider a buzzer. A buzzer is a device that when you apply a voltage to it, it will put out a sound or tone (2.048KHz from your description). However, this unit is really a type of speaker with a frequency response centered around 2k Hz. If one looks at the data sheet, that could be deduced, but the title (and the one in the manufacture’s document) makes one stop and wonder.
I wanted a speaker (piezo or otherwise) and saw this unit. Seeing that it was a ‘buzzer’, I was resigned to a single tone. When I got the units, I discovered that they were ‘speakers’ after all. So I’m a happy camper.