Anti fog is a great anti-fog lens cleaner designed for quick and easy use on your mask or sunglasses. Great if you are in and out of the water a lot. A quick tip at the end of the days diving simple wash mask in fresh cold water and leave to self dry in a bag or its original container. Then before your next dive on the morning of, simply apply Anti fog to the inside of the mask, leave for 10 seconds and afterwards rinse into salt water to wash away any excess and your ready to go. Good vision in the water.