That device is a little USB buzzer. Both the frequency an volume can be controlled. There is even a way to preset simple beeping patterns.
In addition, the Yocto-Buzzer also features two bright leds (one red + one green) and two analog inputs able to read any resistive sensor such as switches, push buttons, potentiometer, reed contact, photo diodes etc....
Long story short, le Yocto-Buzzer is the device you need to get your user's attention, especially if your project is driven by a headless computer.
USB cables and enclosure to be ordered separately.