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K&N Universal X-Stream Clamp On Air Filter 3'' Flange, 4 1/2'' Base, 6'' Top, 4 5/8'' Height


  • Increases Horsepower
  • Increases Filtration
  • Washable and Reuseable Filter
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Pricing: $82.99



K&N X-Stream Top Universal Air Filters take performance to the next level with the addition of a filter within the filter's top adding more filter area for higher air flow and a longer service interval. The X-Stream Air Filter provides awesome airflow and outstanding filtration. When racing, in any environment, racers need all the protection and airflow they can get. K&N delivers. All K&N universal air filters are constructed with ultra-strong molded pliable rubber flanges which absorb vibration and allow for secure attachment and can also be stretched for up to 1/16 inch (1.5mm) to fit in-between sizes. K&N universal air filters are washable and reusable.

Application List



Height: 4.625 in (117 mm)

Flange Inside Diameter: 3 in (76 mm)

Outside Diameter: 4.5 in (114 mm)

Flange Angle: N/A

Finish: N/A


  • RX-3900-1
  • RX-3900-1
  • K&N
  • New

Shipping Information

  • Item Requires Shipping
  • 1.1 lbs.
  • W6.5000” x H7.3000” x L6.5000”

Customer Reviews

Comment Total Reviews (1)

Incredible little filter!
  • Currently 4/5 Stars

Reviewed by: Sean09/18/2018 04:52AM

Product ownership: Less than 1 week

Purchased from: Off Road Warehouse

The sound is spectacular. Very aggressive. Gains tested from one filter to this one noticeable via accessport. This is the sound I want. This is the power I love. Visually, it's simply too small for a MK3 Focus RS intake box in my opinion.

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