W2 Optima White brush heads remove up to 100 percent more stains vs. a manual toothbrush for whiter teeth in just one week. Clinically proven to remove up to 7x more plaque vs. a manual after four weeks of use.Your brush heads replacement will become less effective after 3 months' use, Your smart toothbrush will track how often and how hard you brush and will notify you when it's time for a replacement. Just monitor your blue replacement bristles — when they turn white you'll know it's time for a fresh brush head. SUPERIOR WHITENING: Clinically proven to remove up to 100 percent more stains in 7 days than a manual toothbrush SPECIAL DESIGN: The specially curved power tip makes reaching the teeth at the back of your mouth a breeze. GENTLE and EFFECTIVE: Soft, densely packed bristles remove surface stains and whiten your teeth, while gently protecting your gums NO GUESSING: Built-in brush head replacement reminder lets you know when to replace your brush head, so you don’t have to remember EASY TO USE:Simply click on and off for easy replacement and cleaning.The heads come with caps for hygienic storage and travel. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.