The Time Capsule is a fully featured 802.11n Wi-Fi base station[5] and supports all the same features as the AirPort Extreme Base Station, featuring the same set of ports on the back. Modifications upon the design of the AirPort Extreme Base Station include the addition of the storage hard drive for backups and NAS type file storage which will be available to both Macs and PCs (after installing supplied drivers) on the network. The Time Capsule measures 7.7 inches or 19.7 cm square and 1.4 inches or 3.63 cm high;[5] slightly larger than theAirPort Extreme Base Station and closer to the Apple TV (previous generation model) in volume. This is partly due to the internal power supply which eliminates the requirement for a separate external power supply, enabling a direct connection between the household power outlet and the back of the Time Capsule.