This is a mouthpiece developed in collaboration between Denis Wick and PAXMAN. Tim Jones, principal horn player of the London Symphony Orchestra, was also involved in the development, incorporating innovative ideas found in Heritage mouthpieces for French horn to create a completely new mouthpiece. This is a well-balanced mouthpiece that combines responsiveness and power. It has a unique cup shape and is compatible with PAXMAN horns. Model Number: 5.5 Inner Diameter: 17.40mm Rim Thickness: 4.3mm Bore Size: 4.5mm Backbore Shape: V-type