Briggs & Stratton Air Filter Cartridge/Pre-Cleaner 12.5 - 21 HP 5050K
Genuine Briggs & Stratton air filter cartridge with pre-cleaner for 12.5 through 21 horsepower horizontal crankshaft L-Head and most Vanguard OHV V-Twin engines.  Replaces Briggs & Stratton service part number #394018S (air filter), and #272490S (pre-cleaner).