Tilz Mc William Model #1 This mouthpiece is from Tilz, a long-established German mouthpiece manufacturer representing Europe. It is the model of Fergus McWilliam, a horn player with the Berlin Philharmonic. Inner Diameter: 17.5mm Bore: 4.4mm Cup Depth: Medium Rim: Medium Wide American Shank This is a used item, so there are some small scratches, but it is in beautiful condition. Of course, there is no problem at all with playing.