Specially Designed】:This head is specially designed Unique design ,more dense bristles，stronger vibration and more thorough cleaning. 【Sanitary Packed】: Each replacement head equipped with dust cover then sealed into plastic bag and together packed in paper box. Three layers of protection avoid dust pollution during packing and transportation. 【Teeth Protection】: 95%-98% top of bristle rounded before packaging. Just considering protecting your teeth when brushing in high vibration. The teeth enamel would get worn if bristle was not rounded. 【High cost performance】: A box of 10 pieces can meet your need to change your toothbrush, and the price is more appropriate.Replace brush head every 3 months. 【Medium Bristle】 Plant 0.178mm nylon bristle, which are stiff enough to remove debris, but also soft enough that they don’t damage tooth enamel.