The device doesn't have any buttons on it — there's only a small, circular LCD that reads out your measurements. Since there are no controls, you use your computer to set up the scale — the Aria senses Wi-Fi networks in your area and you can choose from them on your computer. We were told that the Aria is rated for six months of life from its four AA batteries, even though the scale retains a small connection to your router when its in standby so you don't have wait for it to sync before you weigh yourself. The scale has one other trick up its sleeve — it can sense users so a family can use the same device, and there's an interface for selecting users by tapping your feet on the surface of the scale. You can expect to see the Fitbit Aria in black and white for $129.95 in April.