This is a mouthpiece developed by YAMAHA in collaboration with the world-renowned euphonium player Shoichiro Hokazono. It was only sold for a short period, and even then, it was difficult to obtain. No explanation is probably needed. The build and plating quality are, as expected from Yamaha, excellent. A mouthpiece called 53SH was also sold. This was said to be a copy of the Black Hill, but the HOKAZON is said to be an improved version of that.