The Glasfloss ZL Series MERV 10 21 1/2 x 23 5/16 x 1 pleated air filters are designed to out perform other filters. In conjunction with the heavy duty beverage board frame, these filters offer an expanded metal backing to support the synthetic pleated filter media for optimum performance in the most challenging applications. Glasfloss MERV 10 air filters provide enhanced filtration over MERV 8 air filters with no additional pressure drop. This means these filters can capture more pollen, dust and other pollutants than a MERV 8 filter without your system having to work harder to move the air through the filter. As with any 1 inch air filter, these filters should be changed every 30 to 90 days. The synthetic filter media is stronger and more efficient than cotton type media and the heavy duty beverage board frame will resist absorbing moisture, making these filter an excellent choice for for your Carrier, Bryant or Payne air handler listed below. Fits these models and others FV4ANF006, FK4DNB006, FC4DNB060, FC4CNB054, FH4CNB004, FX4DNB049, PF4MNA061, FXM4X6000A, FSU4P4800A, FB4ANF070, FX4CNF060, FE5ANB004, FC4CNB070, FV4CNB006, FX4DNB061, PF4MNB049, FSM4X6000A, FSM2X6000A, FCM4X6000A, FC4BNF054, FX4CNB060, FE4ANB006, FY4ANB060, FX4DNF049, FX4BNF060, PF4MNB061, FSU4X6000A, FSU2X6000A, FVM4X6000, FC4BNF070, FC4DNF060, FB4BNB070, FA4CNB060, FX4DNF061, PF4MNA060, FXM4X4800A, FSM4P4800A, FEM2X6000A