The original patented sonic technology: Naturally whiter teeth and healthier gums guaranteed; Superior plaque removal. No. 1 recommended brand by U.S. dental professionals. Advance a4100. Smartimer. On all Advance models: Extra-soft bristles: Extra-soft, end-rounded bristles are gentle on teeth and gum; Easy-start: Gently increases power over first 12 uses, to ease into the Sonicare experience; Smartimer: 2-minute timer helps ensure dental professional recommended brushing time. Patented sonic technology; Sonicare's unique dynamic cleaning action gently and effectively reaches deep between teeth and below the gumline for a brushing experience unlike any other. Naturally whiter teeth: Clinically proven to significantly reduce coffee, tea and tobacco stains for naturally whiter teeth. Guaranteed. Superior plaque removal: Clinically proven to remove significantly more plaque than a manual toothbrush. Effective and safe to use with braces, dental work, implants and sensitive teeth. Improves gum health: Clinically proven to reduce gingivitis and help shrink periodontal pockets. Inspired by the sonic technology used in dental offices. Developed in collaboration with university researchers to reduce and help prevent gum disease. No. 1 recommended brand by U.S. dental professionals. Sonicare is the power toothbrush brand most often recommended by U.S. dental professionals. Advance a4100 includes: 1 Sonicare toothbrush with brush head (standard size); 1 Charger base with easy-wrap cord; 1 Hygienic travel cap. Replace brush head every 6 months. Full charge lasts for up to 2 weeks of normal brushing. 2 Year warranty. UL Listed. Made in USA.