Review (4/5): Although it met my expectations, others in the household were not as enthusiastic.
I liked them because I am concerned about the overabundance of plastics in our environment and these use less; the handles are bamboo. The brush works fine for me, but others who tried them (you get four of them) complained that the bristles were too firm or too large to fit in their mouths. They also did not like the feel of the handle as it felt like they were putting a stick in their mouths and it caused them to gag while brushing the back teeth. They preferred the feel of the plastic brushes and the different bristle sizes and softness they offer. Some consideration should be given these preferences by the manufacturer if possible. The black charcoal bristles look peculiar, but not a concern.