One of my worst purchases. The brush is very dry, resulting in needing extra effort for a precise result. It smudges even though it claims to be waterproof. It was not worth the money.

POSITIVES:
1) Intense black
2) Good lasting power (it lasted 8 hours for me)*
3) Easy application
4) Convenient brush
5) Very good price

NEGATIVES:
1) From the first use, the brush was dry, so I had to turn it upside down in a pencil case after each use
2) *It is not transfer-proof, so if you rub it, it comes off
3) The brush dries quickly during use

I don't think I would buy it again.

Good but only for a short time... I have bought it twice, and both times after a few uses, the brush would break and become smudged, and it would also dry very easily and not apply any color... Of course, I will not buy it again... The Liquid Sensitive eyeliner brush from the same company is much better!

29/10/20:
I have had it in my possession since July. For someone like me who is not skilled with eyeliner, this solved my problem. Very good tip, very precise brush, very black, very affordable, and it outperforms some benefit, kat von d, and other high-end brands.

Update 09/01/21:
It's as if it dried out and doesn't write anymore with minimal use, because I haven't been using it due to quarantine and it has become unusable. I don't know if I will buy it again. I will give it another chance until I make sure it doesn't write anymore.