K&N Foam Pre-Filters
The K&N Airforce Pre-Filter is a specially designed foam filter wrap made to extend the service interval of your K&N Filtercharger when used in very dusty conditions. They are made from large, open cell foam. The Airforce Pre-Filter will stop 90% of the dirt, yet only add a 2% restriction to the airflow of the filter. This makes foam a great pre-filter.  The Airforce Pre-Filter is designed to be used with K&N Filter Oil and can be cleaned with K&N Cleaner or soap & water.
 
 
       
         

Round Shape

Part Number
Diameter
Height
Color
KNN-253750
14"
4"
Red
KNN-253760
14"
5"
Red
KNN-253770
14"
6"
Red
KNN-255200
16"
3"
Black
KNN-255300
16"
4"
Black
KNN-255400
16"
5"
Black
 

           

Conical Shape

Part Number
Base Dia.
Top Dia.
Height (H)
Color
KNN-250810
6"
5"
9"
Red
KNN-250880
6"
5"
14"
Red
         
         
         
           

           

Oval Shape

Part Number
Width
Length
Height
Color
KNN-251963
9"
20"
3"
Red
KNN-253346
5.5"
9"
3.25"
Red
KNN-253490
5.5"
9"
6"
Red
         
         
           

         

Universal Shape

Part Number
Width
Height
Color
KNN-253900
48"
7"
Red