Piezo Buzzer board

$1.25

These little boards are a bit tricky to judge. You definitely need to make sure they are right for you. To make that easy, I'll jot down a few pros and cons

Pros

They are cheap
They have a nifty mounting hole that holes a 4-40 screw
They are loud
They come with the wires

Cons

The wiring order is odd Vcc,I/O,Grd. not the normal I/O,Vcc,Gnd
IMPORTANT They need to have matching I/O and Vcc voltage inputs. It won't work if your I/O is 3.3V and you put 5V into Vcc

If you can live with that then it's definitely worth a buck twenty-five.