Be sure to replace your One by Sonicare brush heads every 90 days for an efficient brushing experience! These easy-to-replace brush heads come in a back of two.One up your brushing! The One by Sonicare rechargeable toothbrush offers patterned microvibrations to help users create a healthy brushing routine. Once turned on, the brush offers a short buzz every thirty seconds to encourage users to move on to the next part of their mouth. After 2 minutes, the brush offers a longer buzz to indicate that the job is done. The One is wireless - a single charge allows it to function for an entire month! Its removable brush head allows for easy replacement every 90 days. You can even mix and match colors between the handle and brush heads.