【Pterafactry】Dolphin 4BA tip Black 50pcs 's Japan Review

I used it with a 21g barrel that I converted to 4BA.
The threaded side feels a bit thinner than the L lip, but it was comfortable to use.
However, while using it, the inside of the lip had been shaved off by the threads, and it had become loose.
I also feel that it is easy to break, perhaps because it is a little hard.