Review (1/5): Do not buy.
Even if you ignore the comments regarding the dangers of choking hazard, the brush itself is useless. The bristles are not directly attached to the brush's rod, instead, the bristles are attached to a silicone ring which was then placed over the rod. There are about 21 of these bristle rings, but none of the rings are glued to the rod. Basically, the bristles will rotate over your pet's teeth instead of brushing them, even if your pet tries chewing on it.
Chocking hazard, plastic waste, waste of money; the vendor is the only party benefiting from this.