Extra Soft are gentle on kids" teeth and gums. Raised row of blue bristles designed for cleaning chewing surface. Specially Designed for Sensitivity. Gentle, effective cleaning. Features extra soft bristles for sensitive teeth and gums. Works with: Oral-B Triumph, Oral-B Smart Series, Oral-B Professional Care, Oral-B Vitality, Oral-B Pro-Health Power. Will not work with: Oral-B Vitality Sonic, Oral-B Sonic Complete, Oral-B Pulsonic, Oral-B CrossAction Power.