This is the latest model from Backun, the Essence. It's made of grenadilla wood and has a 65mm barrel. With its thick body and heavy rings, and a narrowed bore, it's designed for those who use mouthpieces like the BD5 or B40 series and want to project their sound in large halls. I purchased this, but it doesn't suit my needs, as I mostly play in studios and small halls. Therefore, this is for those who use BD5 or B40 series mouthpieces and often play in large ensembles like wind bands, or in large halls with distant audiences. It's compatible with clarinets from Buffet Crampon, Yamaha, and Leblanc.