On top the router has a 3-watt speaker to help with the setup process. With certain Android devices the speaker emits a specific sound that transmits its code for the phone to connect to it during the initial setup. The speaker also plays a sound to indicate that it's been successfully initialized.
The router has only one LAN port and one WAN port. Google says it cut down the number of ports to reduce cluttering and to entice users to leave the router out in the open in an effort to help increase Wi-Fi coverage.
On the inside, the router also include hardware component for Bluetooth and ZigBee -- an open, global wireless standard used in many "smart" appliances. However, similar to the case of the USB port, these hardware components aren't activated at launch.