Sensitive Replacement Brush Head Twin-Pack. A great starting point for sensitive to normal skin types. Also ideal for use on the décolleté and body. An all-around brush head for most skin types. All CLARISONIC® brush heads are made from a nonporous, soft elastomeric material, resistant to bacterial attachment. All brush heads are precision-designed to oscillate bi-directionally at a sonic frequency. We recommend that you remove the brush head weekly and clean with soap and warm water. Replace your Clarisonic brush head every 90 days. To mount the brush head, align with the 3 notches with the 3 pins on the handle, then push down and twist clockwise.