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21x33x2 Geothermal Air Filters

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Products   MERV Rating Filter Life Annual Cost Value Pack
21x33x2 MERV8 SpiroPure O
MERV 8 Geothermal Filters (6 Pack)
  • $119.99
  • 6 Filters
  • ($20.00/filter)
MERV 8
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3 Months $79.99/yr
Best Value!

$119.99
6 Filters

($20.00/filter)
21x33x2 MERV11 SpiroPure O
MERV 11 Geothermal Filters (6 Pack)
  • $149.99
  • 6 Filters
  • ($25.00/filter)
MERV 11
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3 Months $99.99/yr

$149.99
6 Filters

($25.00/filter)
21x33x2 MERV13 SpiroPure O
MERV 13 Geothermal Filters (6 Pack)
  • $154.99
  • 6 Filters
  • ($25.83/filter)
MERV 13
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3 Months $103.33/yr

$154.99
6 Filters

($25.83/filter)
MERV Rating - Contaminant Removal Guide
MERV Rating   8 11 12 13
Lint & Dust  
Dust Mile Debris  
Pollen  
Mold Spores  
Pet Dander  
Auto Emissions  
Smoke  
Tobacco  
Bacteria  
Note: equals efficient removal of contaminant by filter.