Honestly, it is a copy after a reputable brand, but it feels the same and costs only a fraction.
I bought them for my students, who find the stock mouthpiece of their trombones (usually 12C) too small. I would love to purchase some large-bore ones (4-5 G) as spare mouthpieces for myself, but it seems Thomann doesn't stock them.
I also bought many of their trumpet mouthpieces for my students to try. Because they're low-cost, I can buy quite a few without breaking the bank.
Overall, it is a great product suitable for students and professional players.