*Money Saving 3-Pack* When you order this product, you will save $1.50 off of the normal retail filter price. You will receive 3 replacement evaporator pads. The filter is a plastic sponge-like material and has a round shape. The evaporator pad should be cleaned every six weeks with equal parts of vinegar and water during the heating season and is rated to last up to one heating season under normal operating conditions. Save $1.50 when you order the 3-Pack.