Upgrade your air purifier with this genuine OEM Holmes HEPA Type P replacement air filter. Designed to meet the highest standards in air filtration, this pleated filter with HAPF121D-U4 model number is the perfect fit for your air purifier. Featuring HEPA-type filtration technology, it eliminates up to 99% of airborne particles and allergens, providing clean and fresh air for your home or office. Ideal for indoor air quality and fans, this air filter is perfect for those who suffer from allergies or asthma. Its application is not limited to air purifiers, as it can also be used in heating, cooling, and air systems. Ensure that your home or garden is a healthy environment by choosing this Holmes HEPA Type P replacement air filter.