1. Ask your teacher to buy it for you. The instrument is very accurate. Although the length is the same, what is more important is whether the workmanship is bruised or not. You can't see some flaws. If there are bruises (such as missing intervals), you won't cry in the future, and the music store won't lie to you. So be sure to find a teacher and let him help you choose. Don't buy it without authorization.

2. There are many clarinet brands. Most people use Buffy, a French brand, because the quality is guaranteed. From a novice to a professional, I am a pure Buffy party, and there are managers who buy Buffy from thousands to tens of thousands. When I first learned it, I used Buffy B 12. I bought 4500 at that time, which is very useful for beginners. Now use r13,22000 RMB, entry-level woodwind. Usually thousands of them are rubber tubes. The teacher selected them for me. I suggest you buy Buffy, which is of good quality. Of course, there are clarinets like Jupiter, so I don't think they are very popular.

Actually, Selma can do it, but Selma has tens of thousands of pipes.

Just as I said, you'd better consult your professional teacher.