K&N High-Flow drop-in air filters for the 2009–2017 Nissan GT‑R V6-3.8L are washable and reusable replacement filters designed to fit the factory airbox. K&N states their layered, oiled cotton media improves airflow while capturing contaminants and is intended to provide an increase in horsepower. These filters come two per box and are backed by K&N's lifetime limited warranty.
K&N 09+ Nissan GTR Drop In Air Filter