Wide compatibility across Waterpik Sonic Fusion series - Compatible with SF-01, SF-02, SF-03, and SF-04 models - Check your model number on the bottom of the toothbrush base before purchasing DuPont bristles for quality cleaning - US DuPont bristles provide high toughness, strong bending recovery, and outstanding abrasion resistance - Delivers effective cleaning power while remaining gentle on teeth and gums Effective cleaning for hard to reach areas - Contoured top bristles naturally conform to the shape of your teeth - Slim angled neck and dense bristles reach hard-to-clean areas - Together with the toothbrush head vibrations, delivers up to 8 times more cleaning power than a manual toothbrush Indicator bristle tip for timely replacement - Replace the brush head every 3 months for optimal cleaning performance - The indicator bristle tip fades to remind you when it is time to replace the head to maintain effectiveness Use scenarios - Daily full mouth cleaning: The contoured bristles and dense bristle arrangement provide thorough cleaning across all tooth surfaces - Reaching back teeth and along the gumline: The slim angled neck and dense bristles help access hard-to-clean areas - Regular maintenance reminder: The indicator bristle tip fades to signal when it is time to replace for consistent cleaning performance