Today only, June 20th, you can save 45% on the Arm & Hammer Enhanced Allergen & Pet Dander Air Filters 12-Packs. Snag them for $54.45! (Regularly $99.99) That is just $4.54 per filter. Changing your air filter is the easiest and most basic form of maintenance for any furnace. It is recommended that you change your filter every 30-60 days. This deal will have you covered for at least an entire year! Plus, they will ship free. There are a variety of sizes included, so snag the right one for you now!