According to US Census Data there are 105 million homes in the United States with forced air HVAC systems. According to US EPA research .04” of dirt build up on outdoor air conditioner condenser fins can cost the unit up to 21% efficiency loss. The PreVent wraparound filter is a practical, efficient, long lasting product that helps save time and money, gain efficiency and solve a maintenance problem. 38x110 can be cut with scissors to fit your unit Easy Installation with included elastic cords – No Tools Required Rugged low resistance filter media UV Protected filter 5 Year Warranty Easy to clean, washable Unique Patented Design .