Upgrade the filtration of your Twinfresh Expert from the standard MERV 5 to MERV 13 with this easy to install addition. Fantastic solution for better quality indoor air in areas where smoke, pollen and pollution are prevalent. Dependent on your location, these filters should be changed every 6-12 months.

NOTE: will add approximately 2.5" to the minimum wall thickness required for the Twinfresh Expert installation. Please see the chart below for more information.