Mediocre performance, but it's cheap so what do you expect?
At first, when I recievied my beard straightener brush in the mail, I thought it didn't work. It didn't seem to be doing much of anything to my beard. I then realized that you have to brush in very slow strokes and hold the brush to your face (not long enough to burn, but long enough to be hot and smooth the beard). Even doing that, it doesn't really create great results because it isn't designed well. The grooves on the brush are too wide to truly brush the beard as a real brush would.  It does work, just not very well. I wouldn't really recommend it, but it's cheap so if you do buy it at least you won't be out much.
Rating: 2 stars