DESCRIPTION
Uni Filter® entered the air filtration industry in 1971 with a simple concept, Lets design an air filter that works. Uni Filter chose polyurethane foam as Uni Filter air filtration medium, instead of paper or gauze, because of its superior dirt capturing capabilities and its capacity to be easily cleaned and reused. And the rest is history. Uni Filter’s original “SOCK” and “POD” air filters took the industry by storm and led to the most comprehensive line of foam air filters in the world!
Why foam is a better air filtration medium than paper or gauze?
The principle of how foam air filters work is simple: “Open Cell” Polyurethane Foam is wetted with specially developed filter oil. The “sticky” filter oil is suspended in the path of the dirty air on the strands of the web-like cell structure of the foam. This makes it impossible for dirt to pass through the depth of the filter without sticking to the strands. As the outer strands become loaded with dirt particles, the wetted strands down stream start trapping dirt, allowing the entire thickness to be utilized. This prevents surface loading or air restriction for 80% of the service life of the air filter element. When the filter is sufficiently dirty, it can be easily washed, re-oiled, and re-used.
Two Stage Air Filter for Yamaha WR250F / WR450F (NU-3251ST) by UNI Filter®. For over 50 years, Uni Filter foam air filters have been unsurpassed in both engine protection and overall performance. And their unique two stage design produces more horsepower and more torque than any other air filter.
- Designed to fit in the factory air box exactly like original filter
- The best selling replacement air filter for competition motorcycles and ATVs
- Unique two stage design allows for easy and complete cleaning
- Dual layer of foam, can be serviced separately
- Thin Ultra Seal base is virtually impossible to tear and has a built-in “Grease Groove”
- Made from high-quality materials for ultimate durability
- Manufactured to meet or exceed strict quality requirements
- Made in the USA