Fitbit Aria WiFi Smart Scale Aria syncs automatically and wirelessly through your home Wi-Fi network. Network requirements: Wireless 802.11b, WEP/WPA/WPA2 personal security, Automatic (DHCP) IP setup (static IP configuration not supported) Aria automatically recognizes up to eight different people. Your weight data syncs to your private Fitbit dashboard, so you can control what data you share. Measurement range: 20-350 lbs To set up for the first time, youll need one of the following: Windows XP and later, Mac OS X 10.5 and up, iPhone 4S and later, iPad 3 gen. and later, and leading Android and Windows devices. Aria uses 4 AA batteries - no power cord necessary. Battery type: 4 standard 1.5V size AA batteries (included). Works well and long with Polaroid AA batteries. Water Resistance: Aria is designed to work in a humid bathroom environment. Some condensation due to hot showers, etc. will not damage the scale. The scale should not be submerged. Avoid splashing large amounts of water on the scale. To prevent slipping or accidents, please thoroughly dry the glass top and your feet before stepping on the scale.