Wehrli Custom OUTERWEARS PRE-FILTER AIR FILTER COVER WCF100728 | 4" & 5" AIR FILTERS POWERSTROKE CUMMINS DURAMAX

Extend the life of your air filter with the Wehrli Custom Fab WCF100728 Outerwears Pre-Filter Air Filter Cover. Wehrli Custom Fabrication recommends using an outerwears air filter cover or pre-filter for all WCFab air filters in their turbo kits and intake kits. These pre-filters are designed to deflect damaging debris, preventing clogged filters and maintaining peak airflow and horsepower. Using a pre-filter also extends service intervals for your primary air filter, reducing costs and increasing convenience.

WCFAB pre-filters feature uniform micron openings and are run dry — no oils or additives are needed. Only particles smaller than .005" pass through, while larger debris falls off. Constructed from specially treated woven mesh, these covers repel water without reducing airflow. The hydrophobic treatment lasts 6–12 months, depending on usage. Note: these pre-filters are not waterproof; submerged intake may still allow water entry. Filter sold separately.

Features:

• UV Resistant
• Air Filter Cover
• Puncture Resistant
• Filters Debris Down To 0.005"
• Resistant To Heat Up To 450°F
• Hydrophobic Water-Repellent Treatment
• Enhances Efficiency Of Performance/Exposed Air Filters
• Compatible With WCF100717 4" Air Filter and WCF100719 5" Air Filters

Maintenance Notes:

Pre-filter cleaning frequency depends on driving conditions. Inspect visually as often as normal vehicle servicing. For dirt track or off-road driving, check after every race or trip. For street driving, inspect every 3,000–5,000 miles. Shake off excess dirt; if heavily soiled, soak in mild soapy water, rinse, and air dry before reinstalling. Avoid scrubbing or harsh chemicals to maintain hydrophobic treatment and filter efficiency.