Ford Focus RS Mk2 K&N 57I Cone Air Filter - Focus RS Mk2 2009 - Filters - Panel - Pumaspeed Milltek Ford Performance Tuning Milltek Sport Exhaust Ford Fiesta Focus ST RS Parts Specialist
K&N Engine Air Filter: High Performance, Premium, Washable, Replacement Filter: 2018-2020 FORD (Escape, Focus IV) , 33-3131 - Walmart.com
K&N Replacement Air Filter for Focus RS (E-2993)
K&N X-Stream Adapter Ring - K&N - Air Filters / Intake Kits - Ford Focus RS MK1 / MK2 - Home - JW Racing