I really wanted to like this brush as I love how this brand in particular makes such precise angled brushes, but sadly, this one just isn't as small as I'd have liked. The shape is fatter than expected and thus doesn't produce a very fine line. I much prefer the angled brushes that you find in their larger kits - those are much smaller and more useful.
That being said, I do think this still works for thicker liner applications. Just don't expect to have much success with thin liner (or any type of eyebrow) looks.