Lasts up to 3 months. Excellent air flow - will not restrict efficient operation of your HVAC system. Kimberly-Clark media combines mechanical and electret filtration mechanisms for optimum performance. Four times more efficient on fine particles than mechanical only filters.  

 Air Relief Pleated Air Filters - Excellent air flow and good efficiency on all particle sizes! Commercial quality pleated air filters 1 inch, 2 inch and 4 inch.  

 Synthetic electret/mechanical media. The media is moisture repelling and resists supporting bacterial and mold growth. Double wall frame construction will not break down - even in high velocity commercial systems. MERV 10 at 492 fpm Medium Efficiency air Filter. More surface area at 11 pleats per foot for both 1" and 2" sizes. Four inch filters have 9 pleats per foot.

 MERV on air filters stands for Minimum Efficiency Reporting Value, a standard rating (1-16+) indicating how effectively a filter captures airborne particles like dust, pollen, and bacteria; a higher MERV number means better filtration and more particles trapped, but it also means a denser filter, which requires more airflow from your HVAC system.  

 Common MERV Levels

MERV 1-4: Basic, protects equipment from large debris.

MERV 5-8: Moderate filtration, good for general home use, catches mold spores, pet dander.

MERV 9-12: Better filtration for finer dust, pet dander, and some bacteria.

MERV 13+: High efficiency, captures very small particles like bacteria, viruses, and smoke; often recommended for severe allergies but requires a strong system.