This nano toothbrush is double ultra soft for gentle and effective brushing. It is made with bamboo charcoal bristles. Bamboo charcoal has excellent absorption capabilities. In the same way charcoal filters are used to clean water, the bristles draw odor and impurities from the mouth. Bamboo charcoal is one of the best natural materials at collecting harmful substances and when we put it on your toothbrush it works wonders for your teeth and gums because it attracts and retains a much higher volume of pollutants than a regular toothbrush would.