Oral-B iO Gentle Care Replacement Head Electric Toothbrush Black x2 is ideal for those with a sensitive mouth. Only compatible with Oral-B iO handles, these heads stop you from getting frayed bristles again and allow you to enjoy a professional clean feel every day. As a matter of fact, each head has 4000 high-density thin filaments that ensure a gentle cleanse and protect the gums. At the same time, the bristles are soft and have a specially-designed pattern with an overlay of concave and convex bristle trims so they adapt to the curves of the teeth and gums. On top of that, the thinner outer bristles surround each tooth and enable a delicate cleaning along the gumline. Furthermore, the cushioning outer ring has the smallest diameter bristle filaments of any other Oral-B Electric Toothbrush refill. As a result, you get unique brush heads that offer a gentle energy of micro-vibrations for synchronized and consistent cleaning. Dentists recommend changing the brush head every 3 months for optimum results. Characteristics Good for: regular cleansing, cleansing each tooth individually, sensitive mouths; Presentation: two black electric toothbrush heads compatible with Oral-B iO handles. How to use Fit the Oral-B iO Gentle Care Replacement Head Electric Toothbrush Black x2 on the toothbrush and then apply toothpaste. Then, brush your teeth for 2-3 minutes, preferably after each meal, and before going to bed. Rinse with water. Brush at least twice a day. Finally, remember to change the toothbrush head every three months.