Although adequate for a standard engine, the Focus ST's standard air box can be found lacking when the power levels have been pushed up by a re-map and other modifications.
To help improve the performance of your Focus ST, ITG have developed a new intake. The ITG kit increases the filter area by over 50% and uses high quality three layer foam to improve flow and filtering characteristics. The air intake is mounted down behind the bumper, well away from any power robbing heat under the bonnet. Aside from the increase in power, there are improvements with throttle response and a pleasing, yet unobtrusive increase in intake noise.