Cup holder easily attaches to existing windshield mounting bolts on either side of the dash. This cup holder is STEEL, not aluminum or a cheap plastic version. Cup holder is designed to be mounted by the customer in the rear of their Jeep. Permanent modification is required to secure cup holder and is the responsibility of purchaser.Works on both the rear drivers and passengers side. 3.3 diameter center hole to accept wide variety of cups and mugs. 3.0 deep to help prevent slips and spills. Matte Black powder coated finish.