This 3.5 inch (90mm) adhesive mounting disk allows you to mount any third-party windshield suction mounting pedestal to your car’s dashboard. (Note that the disc is meant to be a bit larger than the mount to ensure a secure fit.) This package includes only the adhesive disk (mounting pedestals sold separately). To apply the adhesive disk to the car’s dashboard, simply remove the paper backing from the back of the plastic 3M dash mount disc, then place and press down on a previously cleaned surface. (Allow 24 hours for the adhesive to cure before securing the base of the mounting pedestal to the center of the disk for best results.) While this disk is meant to be a semi-permanent solution, the disk can be removed from the dash by applying a generous amount of rubbing alcohol or similar adhesive removal product to the area with a cotton swab. Let the liquid saturate the area, then work a long piece of dental floss under the disk to cut through the adhesive until the disk is removed.