The Xperia Play slots into it easily, connecting the 3.5mm headphone jack & USB port for charging. There is an audio jack & cable at the back you can connect to your AMP or speakers for playing music or videos.
When docked, the UI changes to dock mode, which lets you launch the music player, photo gallery etc which is a really nice touch. If you choose neither, the phone reverts to displaying the clock, making it ideal as a bedside dock/alarm clock.
In the pack, you also get a short USB cable, and voucher codes for 3 downloadable Gameloft games.