The A/C Filter Timer eliminates the guess work in replacing your air filters and improves indoor air quality. Eliminate the guess work and save energy by replacing your Air Conditioning and Furnace filter periodically with this practical Filter Replacement Timer. A cleaner air filter helps reduce the possibility of additional damage to your AC or Furnace unit. The unit is compact in size, comes with a wall mounting bracket and a magnet back allowing you to choose the location where you want to place it. The AC Timer will remind you when it is time to replace your filter, making maintenance easier.