Soft rubber-cushioned side arms expand from 2" to 3.5" wide* and adjust up or down (independently) over a 2" range so you can find the ideal grip position. The included T-mount plate attaches to any bracket with standard AMPS hole pattern, such as our Modifry Dash Bracket or the Panavise Radio Bracket. Once the T-mount plate is attached to your bracket the phone holder slides on and off the T-mount. Feedback from customers indicates that some of the newer/heavier phones need the extra gripper arms - see "Related Products" tab.
* The side arms are actually curved, with a minimum distance of 3.5" at the tips of the arms. But the center of the arms (near the back of the holder) is wider, about 3.75". Most phones up to 3 3/4" wide will fit because they are relatively thin and will be gripped in the curve of the arms.