P21S Windshield Wash Booster, 250 ml Measure Bottle Add the pre-measured amount of this powerful detergent to a gallon of your favorite washer fluid. Fill your windshield washer reservoir and streaky, film covered windshields will be a thing of the past. Once you have tried the incredible cleaning power of Wash Booster, you will never go back to plain old blue fluid again. One bottle boosts the cleaning power of 26 quarts of washer fluid.