Features: 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 Filter_x000D_ Material: Plastic_x000D_ Part Number: 491588S / 491588 / 399959_x000D_ Fitment: _x000D_ Replacement for Briggs Side Valve Engines _x000D_ Replacement for Quantum Series 625, 650, 675(Current Engines), Model 12 series_x000D_ Also fits some horizontal crank engines used on generators, cement mixers PackageList: 1 x Air Filter Note: 1. Please double check the part number of your item, matching information is for reference only._x000D_ 2. If you are unsure of the item, please contact us before buying to avoid unnecessary return, thanks!