The Emmi-dent Metallic/Professional 2-Pin Bristle-Head Attachments cleans without abrasive brushing and without vibrations. Our electric toothbrush replacement heads clean using ultrasound wave technology that reaches deep into cracks and crevices down to the gums. The electric toothbrush heads contain Piezo-chip technology to create ultrasound waves. The bristles serve as antennas to deliver targeted waves directly on teeth and gums. Emmi-dent is clinically-proven (Ormed University of Witten/Herdecke)to reliably remove bacterial plaque that can cause cavities, gingivitis, and periodontitis. Only attach the Emmi-dent Metallic/Professional 2-Pin Bristle-Head Attachment to the Emmi-dent Metallic/Professional Ultrasound cleaning device. For perfect ultrasound cleaning performance, we recommend replacing the ultrasound head attachments every 3 months. After this time, the ultrasound transmitting bristles may weaken and result in reduced cleaning effectiveness. Comes with four bristle-head attachments. Will be delivered in blue color only.