Compatible with all Philips Sonicare toothbrushes except Philips One and Kids Powerful sonic technology for thorough and gentle dental care Brush heads with indicator bristles For optimal cleaning results, replace the brush head every 3 months. Indicator bristles show the right time to replace the brush head by changing the bristle color. execution The replacement set consists of 4 premium whitening toothbrush heads in black with a medium hardness - for radiant teeth. Scope of delivery 4 Premium Whitening Brush Heads Notes Additional information can be found in the user manual.