This is a New IR model mouthpiece for French horn by Ailrich (currently EPM). It has been treated with Ailrich's proprietary acoustic treatment, "STET treatment." This acoustic treatment combines heat treatment under strict temperature control with chemical treatment using chemicals to maximize the resonance and vibration of the metal. It is gold-plated and made of solid nickel silver (nickel silver), which is no longer standard production (custom order). IR 2VL Inner rim diameter: 17.50mm Cup shape: V cup Depth: Medium Bore size: 4.5mm Shank: 5/100 taper (American shank) Material: Nickel silver Please refer to the fourth photo for the specifications. It responds very well, and the low range, in particular, has a core sound that feels good (this is just my personal opinion). I am selling it because I switched to an instrument with a shank that doesn't fit. It has only been used for trial playing, so it is like new, but there may be minor scratches, so please refrain from purchasing if you are sensitive to such things.