A PCB mount buzzer is a small, surface-mount device (SMD) buzzer that can be mounted on a printed circuit board (PCB). They are designed for use in a variety of electronic devices. 
PCB mount buzzers have two pins: 
The bigger pin should be connected to positive supply.
The shorter one should be connected to ground connection.
They have an operating voltage range of 5-12V. If you provide a square wave of 5V, it will create a good sound. 
PCB mount buzzers are great for adding audio alerts to electronic designs. They can be used in: 
DIY and breadboard projects
Actual electronics production
Prototype boards