Specification:

• MERV Rating: 11
• Filter Life: 6-12 Months
• Nominal size: 20 x 25 x 4
• Actual size: 19 7/8" x 24 3/4" x 4 3/8"

Functionality - E1=0.3 to 1.0 microns (small particles), E2=1.0 to 3.0 microns (medium particles) and, E3=3.0 to 10.0 microns (large particles)

MERV 11 Rating - E1= 20%, E2= 65%- 79%, E3= 85%-100%