The Aidoni US Bore clarinet barrel has a narrower bore than the Orginal and is the result of a long and meticulous process of experimentation. It has been co-created by Martin Fröst over a four-year period. Since 2016, Martin uses Aidoni grenadilla barrels on all his clarinets. The barrel has an inner plastic tube with a reverse taper, and the tube is partially covered with a thin brass pipe. The result is a perfectly balanced barrel with exquisite intonation, and a resonant and focused sound. The use of a plastic inner tube allows a precisely measured bore, keeping its dimensions constant. The Aidoni barrel reaches the right temperature and pitch faster than a traditional wood barrel. Avaiable in Grenadilla and Cocobolo because of the narrower bore the same barrel is suitable for both Bb and A clarinets.