K&N PERFORMANCE AIR FILTER SUBARU IMPREZA WRX LEGACY

K&N PANEL FILTER 33--2031 TO Suit : 
1992-2006 Impreza (inc WRX & STI models) GC8, GF8, GDA, GDB 

Forester 1997-2002 turbo & non turbo 
SF5,SF9 
SG9 , SG5 Inc STi 

Legacy 1989-2003 BC, BF,BH, BE, BG, Turbo & non Turbo 

K&N's replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. We make over 1,200 different replacement air filters for virtually every vehicle on the road. These filters are washable and reusable and are custom designed to fit into your existing factory air box. Their drop-in design means adding performance is simple. With most vehicles you simply remove the disposable air filter and replace it with a K&N.
The Importance of Oil
A K&N Air Filter is made of 4 to 6 layers of cotton gauze sandwiched between two epoxy-coated aluminum wire screens.  The cotton is treated with a specially formulated grade of oil causing tackiness throughout the cotton’s microscopic strands.  The nature of the cotton allows high volumes of airflow, and when combined with the tackiness of the oil creates a powerful filtering media that ensures engine protection.