Uni Filter NU-3218ST Multi-Stage Competition Air Filter for Yamaha

The Uni Filter NU-3218ST is a high-performance multi-stage competition air filter designed for Yamaha powersports applications. Constructed from premium open-cell polyurethane foam, this reusable filter delivers superior filtration and airflow for demanding riding conditions.

Key Features:

• Multi-stage foam construction provides progressive filtration throughout the entire filter depth
• Open-cell polyurethane foam works with specially formulated filter oil to trap dirt particles
• Prevents surface loading—utilizes 80% of filter thickness before airflow restriction occurs
• Competition-grade design for maximum performance in harsh environments
• Washable and reusable—clean, re-oil, and reinstall for long-term value
• Direct replacement for Yamaha OEM air filter applications

How It Works:

The foam element is treated with Uni Filter oil, which creates a sticky barrier suspended on the web-like cell structure. As air passes through, dirt particles become trapped on the oiled strands. Unlike paper filters that load from the surface inward, the multi-stage foam design allows downstream strands to continue trapping dirt as outer layers become saturated, maintaining consistent airflow throughout the filter's service life.

When the filter becomes sufficiently dirty, simply wash it with appropriate cleaner, allow it to dry, re-oil with Uni Filter oil, and reinstall. This reusable design makes the NU-3218ST an economical and environmentally friendly filtration solution for serious riders.