The K&N E-4210 replacement air filter is constructed with an oil-free synthetic media. The E-4210 provides excellent filtration in order to protect your engine from unwanted dust particles. This K&N air filter can be cleaned and used again, lasting the life of the engine. K&N E-4210 is easy to install will fit into your factory air box. K&N E-4210 air filter will fit in select Briggs & Stratton lawnmowers, as well as other small engine applications.