491588S Flat Air Filter Cartridge for 491588 399959 4915885 625-675 Series 3.5-6.5 HP Engine Lawn Mower Parts 12PCS

What It Is

This is a 12-pack of flat air filter cartridges (model 491588S) designed for small engines in lawn mowers, specifically 3.5–6.5 HP engines from the 625-675 series. It replaces OEM part numbers 491588, 399959, and 4915885, intended for routine air filtration maintenance on push mowers, riding mowers, and other outdoor power equipment.

Fitment & Compatibility

Before buying, verify your engine’s OEM part number: this set replaces 491588, 399959, and 4915885. It fits most 3.5–6.5 HP engines from Briggs & Stratton, Tecumseh, and similar brands in the 625-675 series. Check your mower’s air filter housing dimensions—this cartridge measures approximately 3.5 x 2.5 x 0.75 inches. Not compatible with larger engines (7+ HP) or non-standard filter housings. If your engine uses a different OEM number, measure your old filter to confirm fit.

Key Things to Know

• Quality: Aftermarket, but rated 4.8/5 from 578 reviews—users report it seals well and matches OEM performance.
• Installation: Simple—remove the old filter, clean the housing, and press in the new one. No tools needed.
• Gotcha: This is a flat cartridge, not a round or pleated type. Double-check your housing shape before ordering.
• Value: 12-pack for $15.99 is cost-effective, but you only need one per season—buying a single may be cheaper if available.

Should You Buy It

Yes, if you own multiple mowers or small engines using these filters—the 12-pack saves money and ensures you have spares. Not ideal for a single mower unless you want to stock up for years. Verify your engine’s OEM number first, but for 625-675 series engines, this is a reliable, easy replacement.