Philips Sonicare 3100 HX3671/11, 1 pc, Sonic toothbrush. Sonic technology combined with our brush action gently removes plaque up to 3x better than a manual toothbrush. Cleans even interdental spaces effectively, improves gum health, and is easy to access the back of the teeth. It helps prevent tartar and tooth decay and does not irritate sensitive teeth and gums. Features a built-in timer. Sonic technology for naturally whiter teeth and improved gum health.