Review (1/5): Dissapointed.  Barely any boar bristles, mostly nylon.
When I brush with this I don't feel it going through the layers of my hair. I being able to feel the bristles through my hair if I place my hand on the other side when I brush. This doesn't do that. I do have rather thick hair, so it may not be the case for people with thinner hair.
Another reason for my disappointment with this brush is that it is mostly synthetic, nylon bristles. My hair becomes frizzy after using it.
There is also a terrible chemical smell. I've actually had this brush for years now. (writing a review super late because my good boar bristle brush broke and I had to use this one again...oh boy, the difference). Even after years of owning this brush and washing it occasionally it still stinks like chemicals.
I kept it because I needed a brush for my long haired dogs anyway. I went and bought a genuine boar bristle brush elsewhere.