Simply add Rain‑X Washer Fluid Additive to water or any windshield washer fluid to apply Rain‑X technology.Tired of streaks and marks on your vehicleâ€™s windshield? Rain-X Windshield Washer Fluid Additive makes it look brand new. Itâ€™s simple. Add Rain-X Washer Fluid Additive to water and let your windshield wipers do all of the hard work. Just four ounces is enough to treat an entire gallon of water. Not only will your car look its best, but youâ€™ll feel better as you enjoy increased visibility while you drive, improving safety for you and all of your passengers. To use, simply mix Rain-X technology with water or premix washer solution to improve windshield cleaning Designed to repel rain, resulting in a cleaner, clearer windshield, increased visibility, enhanced comfort and ultimately a safer driving experience for you and your entire family 16.9 FL OZ bottle with easily resealable top for multiple uses.