RUGGED CONSTRUCTION: K&N Advantage Plus Air Filters are manufactured with durable, premium materials to last for up to 18,000 miles of use. EXTENDED LIFE 18K: K&N Advantage Plus Air Filter provides 50% longer life compared to standard 12,000-mile filters. SUPERIOR FILTRATION & PROTECTION: K&N uses a premium filter media that provides up to 99% efficiency to protect your engine. REPLACE EVERY 18K Miles: Engine air filter only needs to be replaced every 18,000 Miles under normal highway driving conditions (1.5 years based on the average miles driven per year of 12,000 miles) NO-HASSLE WARRANTY: 1-Year Limited Warranty.