The FlexFit Tech brush features soft rubber links for optimal interdental cleaning and excellent teeth protection, with an innovative 5° design for deep cleaning below the gum line. It uses unique DuPont™ and self-developed bristles for exceptional plaque removal and a comfortable cleaning experience, plus a delicate tongue cleaner for fresher breath. Compatible with all Oclean adult toothbrushes, it is recommended to replace the brush head every 2-3 months. Bristle firmness: Soft