Amazon offers the PetSafe Drinkwell Premium Carbon Replacement Filter 3-Pack for $4.19 with free shipping via the steps below. That's the lowest price we could find by $4. To get this deal:
  1. View the PetSafe Drinkwell Premium Carbon Replacement Filter 3-Pack for $5.59
  2. clip the 20% off coupon on the product page
  3. order via Subscribe & Save for a final price of $4.19
Note: Be sure to cancel Subscribe & Save after your order ships to avoid being billed for subsequent shipments.