Filtrete Air Cleaning Filter, Replacement Filter For The FAP01-RS, Small Room Air Purifier & FAP02-RS, Medium Room Air Purifier. Advanced Filtrete Filtration Technology Effectively Captures 99.9% Of Airborne Particles & Allergens, Filter Change Indicator Senses The Particle Accumulation On The Filter, Taking The Guesswork Out Of Filter Change, No Ozone Generation. Filter Size 15 in x 9 in x .75 in.