Say goodbye to manual brushing and hello to Sonic technology. Sonicare technology gently pulses between teeth for more effective brushing than manual. Removes up to 5x more plaque than a manual toothbrush. Pressure sensor and two intensity settings protect from over brushing. 2 Minute SmartTimer with QuadPacer ensures brushing time. Long battery life with battery light indicator. One charge lasts up to 2 weeks. Built-in rechargeable Lithium-ion battery. Includes (2) 4100 Toothbrushes w/ Optimal Plaque brush head.