When the phone rings .. a signal is sent through to the small extra bit of plastic (thinking its a car kit) -- the small device then plays your choice of amazing, new sounding ringtone you've chosen using buttons on the kit..

Everyone thinks you've got a top-of-the-line phone, where as in reality the extra 'ringtone' gadget only cost you $5 from the market rather then the $380 the actual entire nokia TX6000 phone would have cost you!