since I no longer use my `` stock cd\/cassette\/am . FM radio '' , as all my music be on my Samsung Focus -lrb- finally find a 32 gig expansion memory chip that be WINDOWS PHONE 7 CERTIFIED . this tuck into the CD aperture , and there be a thick plastic knob that tighten the grip by expand once place inside the CD slot and turn . there be a push button release to remove you phone\/gps from the mount . some folk be complain that they could not get sufficient `` grip to tighten it all the way '' . SWIVEL the PART that actually \*\* hold \*\* the phone upside-down . that will give you all the `` room '' you need . now that it be tighten , turn it back over and it be ready for use . I also use the MONSTER CABLE CASSETTE TAPE ADAPTER and use the mp3 from my Samsung Focus . have not take this puppy out for a `` test drive to see how it do over bump and such '' . once this get the `` road test '' , I 'll edit my review accordingly . 8.19.2011 8.21.2011 ~ WOW , I be impressed , drive this over the toughest road in my truck , it do BOUNCE , BUT SO DID the TRUCK and EVERYTHING in IT !! ; -rrb- -rrb- this unit pass my `` acid test '' , so it be `` Christopher Approved '' . BTW , if you want to see the video of this in operation , go here to the MOUNTEK SITE : -lrb- ... -rrb- btw , they say `` shipping between Aug 21 and 26th '' . I order this on Weds Aug 17 , 2011 and it arrive USPS on Friday before noon . Pretty fast\/slick . I be impressed with that quick a delivery . Christopher