Oral-B io 4 Duo Black & White \ \ Electric Toothbrushes Black & White \ \ The io 4 electric toothbrush features Oral-B's best technology, combining a dentist-inspired round head with micro-vibration bristles for a professional feel of ultimate cleaning at home. \ \ The smart pressure sensor helps you brush neither too hard nor too soft to better protect your gums. The gum protection feature notifies you via the free Oral-B app when you have brushed with too much pressure. \ \ Replace your Oral-B io brush head every 3 months for best results. \ \ Contents: \ \ \ 2 io4 handles (black & white) \ 2 brush heads (ultimate clean & gentle care) \ 1 charger \ \ \ Features & Benefits: \ \ Oral-B's best clean with revolutionary io technology for a professional clean every day. combines oral-b's unique round brush head with gentle micro-vibrations for a fresh, clean mouth feel and 100% healthier gums in one week compared to a regular manual toothbrush \ \ 4 brushing modes to personalize your brushing: daily clean, whitening, sensitive teeth, very sensitive teeth \ \ the smart pressure sensor turns red, white or green to alert you when you're brushing too hard, too soft or with just the right pressure \