K&N Replacement Air Filter (33-2873) Ford > Focus > Mk3 2010-2018 > ST250 2010-2015 and the spring can be

and the spring can be replaced to match the boost of tuned cars

and the outstanding stiffness to weight ratio that is needed to stay competitive in today's racing industry

we will test several different cores for each application

The intake diameters on these air intakes have been carefully tuned to provide exactly the correct quantity of air ensuring solid consistent power gains throughout the rev range without any loss of low-end torque

K&N Replacement Air Filter (33-2873) Ford > Focus > Mk3 2010-2018 > ST250 2010-2015 and the spring can beK&N washable, reusable High Flow Air Filters feature a state of the art design of layered, oiled cotton media engineered to improve airflow and capture contaminants, and are designed to provide an increase in horsepower. Each performance air filter is reusable, engineered to last for the entire lifespan of your vehicle, and backed by K&N's No Hassle Lifetime Limited Warranty. K&N drop in replacement filters are designed to install easily into your