The Sonicare DiamondClean HX9903/21 rechargeable sonic toothbrush features Smart brush head sensors Smart brush head recognition 4 modes and 3 intensities. This rechargeable toothbrush delivers the best plaque removal gum health and whitening performance. Choose from Clean White+ Deep Clean+ or Gum Health modes and 3 intensity levels - high medium low for a custom cleaning experience. Proven to deliver up to 100% less gum inflammation and up to 7x healthier gums in just two weeks. Real-time tracking on the Philips Sonicare app that lets you know when you've achieved a thorough clean and coaches you to be a better more mindful brusher. The DiamondClean HX9903/21 has built a scrubbing sensor into your handle as a gentle reminder to reduce scrubbing so as to improve your technique and get a gentler more effective clean. With its densely packed central stain removal bristles it is clinically proven to remove up to 100% more stains in just three days. Its charging glass can be used for charging or to rinse your mouth after brushing. A USB charging travel case is also included to allow you to charge your toothbrush on the go.