aFe 21-91103 Magnum FLOW Pro DRY S Momentum Replacement Air Filter

Vehicle Fitment

• Universal - not vehicle-specific. Designed as a replacement filter element for aFe Momentum intake systems using a matching 3.5" inlet flange and inverted conical shape

Fitment Notes

• Confirm your specific aFe Momentum intake system calls for this filter size and shape before ordering, as Momentum kits use several different filter dimensions across applications

Features

• Pro DRY S media: three layers of oil-free synthetic filtration for easy maintenance
• Progressive layering maintains strong airflow and dust-holding capacity even as the filter loads up
• Deep, open pleats increase usable surface area for improved flow
• 100% polyurethane top and base with integrated bump seal for a tight, no-leak fit
• Washable and reusable across multiple cleaning cycles
• Easily recharged using aFe's Power Cleaner (no oil required)
• Best suited to street use

Specifications

• Shape: Inverted conical
• Filter Media: Pro DRY S, oil-free synthetic (3-layer)
• Inlet Flange Inside Diameter: 3.5 in
• Base Diameter: 5 in
• Top Diameter (inverted): 4.5 in
• Height: 7.5 in
• Frame Material: 100% polyurethane

Included Components

• 1x aFe Magnum FLOW Pro DRY S Replacement Air Filter

Product Description

The aFe 21-91103 is a Pro DRY S replacement filter designed to fit aFe's Momentum intake systems that use a matching 3.5-inch inlet flange and inverted conical shape. Its three-layer synthetic media is engineered for strong airflow and solid dust-holding capacity, all without the need for oiling - making it a low-maintenance option for daily-driven performance builds.

The filter's 100% polyurethane construction, top and base, includes an integrated bump seal that keeps a tight, no-leak connection to the intake tube over the filter's service life. Deep, evenly spaced pleats maximize usable filtration surface area, helping extend the interval between cleanings compared to a flatter, more restrictive design.

This filter suits owners of a compatible aFe Momentum intake system who need a replacement element, or who are building a custom intake and want a filter matching these specific dimensions. Because Momentum kits span many different filter sizes across vehicle applications, it's worth double-checking your intake's original filter spec before ordering.