This isn't a specific ocarina, I don't think, but most, if not all, LOZ ocarinas are not good ocarinas. They're generally out of tune and don't have very good tone. If you want a much better ocarina, check out Focalink. They have a line of plastic ocarinas that are very good. They're very affordable at $25, nearly indestructible, and have great tone. I highly recommend them.
Here's the one I bought: http://www.steinocarina.com/productsDetail.php?id=147