10Pcs Computer Internal Speaker Buzzer PC Case Buzzer Desktop Speaker Mainboard for Computer Repairing

What can I say? It's cheap and it works.

I got these so I could hear the simple beeps of the boot sequence on a complicated custom server. They do the trick!I only needed one, but then though of other projects that could bring the beep.

used on Arduino.uno and ESP8266 Volume could be louder

Came fast but also was a few broken. Guess that's what u get for trying to go the cheap route.