This is a barrel for an E-flat clarinet. I believe it's 41mm. It's made by Hakam Din and was imported from the United States. It's cut back, so you can also use B-flat clarinet reeds. It's made of cocobolo, which produces a softer tone than grenadilla. It has a similar feel to a Backun barrel, and I haven't noticed any particular issues. The color is also beautiful. It fits Leblanc (probably also Noblet). I haven't tried it on others, but you may need to adjust the cork. I mainly use grenadilla, so I've decided to sell it while it's still in good condition.