It consists of two units which can be stacked or separated via a cable of about 1 metre in length. The lower black unit is the subwoofer (low, bass frequency speaker) which is rated at 15 watts sound output. This has a permanently attached mains cable to a 2-pin plug enclosed in a 3-pin UK adapter plug (it was purchased in the UK). The unit is rated to run from 110V to 240V so the adapter plug could be removed for use in the US, Japan, etc. There's a mains on/off rocker switch on the same side as the mains cable entry, and on the other side there's a fixed cable that plugs into the silver top unit.
The cable that runs between the subwoofer and top unit cleverly carries power up to it and also audio from the top unit down to the subwoofer at the same time.
The silver unit on top is the mid-range and tweeter stereo speakers rated at 5W of audio power per channel. On the rear, the combined power and audio lead from the subwoofer has to plug in. Then you can optionally plug in the 3.5mm stereo jack to 3.5mm stereo jack "line in" lead so you can feed in audio from any standard line-level source such as a TV's sound / sound-bar output, a standard phone with headphone jack, computer audio output, etc. The aerial lead (white in the photos - supplied) is for use when a K800i or other fastport phone is plugged in at the front, and improves the FM stereo reception as it is connected through to the phone dock connector inside the unit.
A K800i or similar fastport phone clips in and stands up at the front of the unit. You can operate the phone as normal and all audio is piped through the amplifier and speakers. E.g. MP3s playing via the music player app, or sound from the phone's FM radio. Phone wake-up alarm bell sounds and ring-tones (when the phone rings) are also amplified There's a miniature remote control supplied (working on its original CR2025 button-cell battery, replaceable) which has controls for volume up/down, bass up/down, treble up/down, a button to cancel the bass/treble adjustment, surround sound effect on/off and "function" which switches between audio from the plugged in phone and the "line in" socket (and 3.5mm stereo jack lead, supplied) on the rear.
With the volume on the phone turned up to maximum and the volume on this system turned up to maximum, the sound is impressively LOUD - more than loud enough for a room in a house and you'd probably have other people complaining at you to turn it down, particularly with the bass level set to maximum and the subwoofer unit on the floor or a cupboard or similar surface that resonates with the bass. It's an impressive amount of volume and bass for such a small unit but both volume and bass can be set to something very low if you prefer. The surround-sound effect (derived from normal stereo sound) is also quite effective for a unit that has the mid-range/treble speakers so close together in one unit. The subwoofer unit can of-course be hidden behind some furniture for example, so all you see is the small silver mid-range and treble unit but you get full frequency-range sound filling the room.
The silver unit has controls on top for volume up/down and "function" to switch to line input, and LED indicators showing power-on, whether line-input has been selected via the "function" button and whether surround sound is on or off.
There are marks on the silver unit - visible on the top edge and rear face as shown in the photographs. These are cable storage marks which I've tried to remove but they feel "in" the surface so they're not coming off. There's a scratch on one of the mirror-silver ends of the upper unit and the bottom face of the mini remote is slightly yellowed from sunlight. These are all the faults this system has - everything else looks pretty perfect (as new) and all the functions work with or without a phone attached.
You could just use this with any phone by propping it up at the front between the fastport connector and front face of the unit, plugging in the 3.5mm line-in jack and switching over to "line in" via the function button, otherwise if you have a k800i or similar fastport phone you get the convenience of just clicking it into the front connector. Could also be used as a sound bar for a TV, or as an amplified speaker system for a PC or laptop. I'm sure you could come up with something to cover the fastport connector at the front so it just looks like something to stop your phone slipping forward.
If you're an electronics whizz you could buy a fastport female connector (they're sold on Ebay) and wire to it according to the audio pin-out (fastport to phono / 3.5mm jack converters are also available on Ebay which would give a clue as to the wiring required). Then you'd have an additional audio input and the "function" button would switch between the two (fast port audio and line-in audio on the rear).
A rather strange and whacky piece of kit, but what else would you expect from Sony? Dates from around 2007 plus or minus a year which is when I purchased it new (for several hundred pounds). Not used with a phone at all (despite the fact I owned and still own the k800i I purchased it for), so the fastport connector is not warn and has a very positive "click" with a fastport phone when plugged in. Not actually used very much, hence its condition being very good to excellent overall.
Top unit is about 205mm long, 55mm deep and 52mm tall with the the dock sticking out at the front. The base is about 205mm long, 130mm deep and about 72mm tall. Together (one unit on top of the other) it's about 125mm tall.