Display pack of 1 (394018S) air filter and 1 (272490S) pre-cleaner. This oval style, pleated-paper air filter provides superior protection against the destructive effects of dirt ingestion. Used on select 12.5 HP through 21 HP horizontal crankshaft L-Head twin cylinder, and most Vanguard OHV V-Twin engines, this OEM part ensures proper fit and performance to maintain the life of your Briggs & Stratton engine.