Feature:1. Part Number: According to the original factory specifications, replacing part numbers are 491588S / 491588 / 399959.2. Applicable Model: Air filter cartridge, replacement for Briggs, replacement for Quantum Series 625, 650, 675(Current Engines), Model 12 series.3. Good Performance: Protect your engine from dirt, dust and keep it running at peak performance by replacing the air filter.4. Prolonging Engine Life: Improves airflow and prolongs engine life by providing clean filtered air while running.5. Long Service Life: Large filtering area and long service life. We recommend replacing your filters every season for best performance.Specification:Item Type: Air FilterMaterial: PlasticPart Number: 491588S / 491588 / 399959Fitment: Replacement for Briggs Side Valve Engines Replacement for Quantum Series 625, 650, 675(Current Engines), Model 12 seriesAlso fits some horizontal crank engines used on generators, cement mixers.Package List:1 x Air FilterNote:1. Please double check the part number of your item, matching information is for reference only.2. If you are unsure of the item, please contact us before buying to avoid unnecessary return, thanks!