This precision crafted Japanese mouthpiece from legendary Ishimori workshop! It has Guardala-like narrow rails and a step baffle to bullet chamber. It is moderately bright yet flexible with great projection, again, like a handmade Guardala Studio or something. Condition of this one is near mint, and it has a Selmer ligature with it as well. Tip opening measures 0.100″.
These sell for $625 when you can get one. Their site says “Limited production mouthpiece. A stainless mouthpiece with large bore with a shorter high baffle. Its deeper chamber provides brighter sound in the high range as well as soft and rounded sound in the low range.”