Bolkin 2-in-1 Universal Car Windshield or Vent Mount Holder (black) 2-in-1 design for both windshield and vent The extendable arms are compatible with most smartphones and GPS devices. There is a button on the holder to adjust the width( 4.5cm to 9.5cm) so that it can fit your smartphones or GPS. Press the button, the arms will be extended. Press the button and compress the arms manually at the same time, the arms will be shortened The soft cushions at the arms of the holder can help protecting phones or GPS devices from scratching The windshield holder can be rotated 360o and you can adjust your view angle easily The twist near the suction cup of the windshield holder can help lock and unlock the suction cup to the windshield or any smooth, clean and flat surface easily. Turn the twist clockwise, and the suction cup will be locked on the windshield. Turn the twist anticlockwise, and the suction cup will be unlocked.