Maskview is constructed with the strongest commercially manufactured magnet available to date.  The neodymium Rare Earth magnet can withstand high temperatures.  It is covered in a corrosion proof resin to withstand weathering.  The magnets are placed with the soft felt against the lens to prevent scratching.  The size has been carefully considered to allow easy grabbing with a gloved hand; yet small enough not to obstruct your vision.  Maskview is placed on the upper corners of your mask out of sight until ready to use.  Clearing is usually accomplished with 2-3 quick passes.  Store it back in its original position, out of sight, until it is needed again.