Compatible with SOOCAS X1/X3/X3U/X5 Features: 1. Soft DuPont bristles, correct for sensitive teeth to apply 2. Ultrasonic electric toothbrush can effectively get rid of plaque and decrease gingival necrosis. 3. Adopt DuPont American tynex usual zero bristles bristles,gently for your teeth. 4. zero bristle tip diameter, deep clear the gap between enamel 5. Indenpently sealed packing, far more secure to use. 6. Please replace the toothbrush heads each three months 7. when you've got any questions on the toothbrush model, you'll search the recommendation of guest service. Thank you.