GYEON Quartz Q&sup2; AntiFog 120 ml Hydrophobic Windshield Coating Condensation or fog is mainly caused by dampness in the car, or large temperature differences between the inside and outside; Q AntiFog solves these issues in one application that will prevent your windows fogging up again for at least 2 months. A 120ml bottle of Q AntiFog will be sufficient to protect all glass surfaces for more than one winter season in several vehicles. One application for 6 large windows should use a maximum of 20ml of product. Clean the surface with QM Glass and ensure the finish is smudge or streak free. We recommend using QM Prep before the products application. Apply the product in a criss cross motion. Leave for a few minutes and wipe off.