Replace your brush head every 3 months to relive that new brush feeling. Do you want your electric toothbrush to be tailored to your oral hygiene needs? Experience the Cross Action toothbrush head designed by the #1 dentist recommended brand worldwide - Oral B. The crisscross bristles are set at a 16 degree angle to effective clean along the gumline and reach deep between the teeth for 100% more plaque removal. Perfectly angled bristles engineered for optimal tooth coverage. 4 refills in box. Replace your brush head every 3 months to relive that new brush feeling. How to Use It Dentists recommend changing your brush every 3 months. Indicator bristles signal time to change brush head. Good To Know Do not use on children under age 3. Replace brush (head) every 3 months or sooner if brush head becomes loose due to damage.