Maybe the title’s question isn’t accurate. The USB device is a USB speaker with the shape of cannon, and a combination of two.
The case of the cannon-shaped USB speaker is made with wood. The speaker can produce 2×2.5W of power output by USB port, and can connect PC, iPod or other audio devices with 3.5mm jack.
The wooden cannon USB speaker is available at USBGeek (Unavailable). Each one costs $22 USD. Grab one if you want music out like shooting.