491588S Air Filter for Lawn Mower, 491588s 491588 Replacement Flat OEM Air Cleaner Cartridge Compatiable with Toro 20332, Craftsman 33644, 2 Packs

What It Is

This is a replacement flat air filter cartridge designed for small engines in lawn mowers, tractors, and zero-turn mowers. It traps dirt and debris before they enter the carburetor, protecting engine performance and longevity.

Fitment & Compatibility

Before buying, check three things:

1. Measure your old filter – This filter is roughly 7.5” x 4.5” x 0.75” (flat, rectangular). If yours differs significantly, it won’t seal properly.
2. Confirm your model – Directly fits Toro 20332, Craftsman 33644, and many others using OEM part 491588S. Also replaces 491588, 491588S, 491588MA, 491588M.
3. Cross-reference – Common on Briggs & Stratton, Kohler, Kawasaki engines in mowers, tractors, and zero-turns. Check your engine’s air filter part number online or in the manual.

This is a non-OEM aftermarket filter. It matches OEM dimensions but may have slightly different foam density or paper pleating.

Key Things to Know

• Quality is fine for most users – 4.7 stars from 290 reviews suggests consistent fit and filtration. Some report slightly looser foam than OEM; still works if it seats fully.
• Installation is trivial – Remove the air filter cover, swap the old cartridge, and close. No tools needed. Ensure the gasket/seal ring is present and undamaged.
• Common gotcha – If your engine has a pre-filter (foam wrap), reuse it unless it’s crumbling. This kit includes only the paper cartridge.
• Replace yearly or every 50 hours – More often if mowing in dusty/dry conditions. A dirty filter chokes airflow, causing hard starting and power loss.

Should You Buy It

This is a solid budget-friendly choice for homeowners who need a quick, reliable replacement for a standard flat air filter. It won’t outperform OEM in a heavy-duty commercial setting, but for routine mowing on a Toro or Craftsman, it’s a perfectly good value at $7.69 for two.