I don't know what you're talking about. E-flat clarinet (tenor clarinet, very short kind), B-flat clarinet (ordinary clarinet), A-flat clarinet (slightly longer than B-flat, different timbre), alto clarinet (E-flat, bottom bend). Bass clarinet (B flat, that is, the extra-large type, the second section is S-shaped, the bottom section is bent upward, and there is a bracket below, so you can only sit and play). There are also double bass clarinet and so on, all of which are derived. Is there anything else you want to know?