HX3631/06. No. 1 recommended brand by dental professionals. Better check-ups guaranteed (Use Sonicare PowerUp for 90 days and if you are not 100% satisfied for any reason, we'll give you a full refund). Helps reduce cavities. Helps whiten teeth. 1 year warranty. Dentists recommend replacement every 3 months. Reminder bristles fade when replacement is needed. C UL US listed. Personal hygiene appliance 1T26. 3VDC (Two (2) AA alkaline 1.5 volt batteries). Recyclable packaging material. For all questions, call: 1-800-682-7664. www.philips.com/sonicare. Made in China.