The Mirror in the fog free shower mirror is a thin electric heating pad that is mounted behind your bathroom mirror to prevent it from fogging up. By heating the mirror it will keep your bathroom mirror clear in the steamiest of conditions even if the doors are closed and the fan is off. The fog free shower mirror is not a spray or coatingfog free shower mirror will ever form on a heated mirror. The result is that your bathroom mirror is always working because fog free shower mirror is there to insure a fogless mirror, especially when you need it most. that has to be reapplied over and over but is completely maintenance free and out of sight. The cost is just pennies a day. Your bathroom mirror will remain fog free because