Totally Disposable and Convenient to Replace. Unlike washable filters, NaturalAire +Plus is convenient to use and easy to replace. Under normal conditions, the filter provides up to 90 days filtering of your air. Sealed For Your Protection. Unlike unwrapped filters that collect dust and dirt on sitting in storage, NaturalAire +Plus is sealed fresh at the factory, so it is 100% clean and ready to work when you unwrap it. Protect Your Home and Family From Airborne Microparticles. Ordinary furnace filters are designed to protect heating and cooling equipment from the insulating properties of relatively large airborne particles. The NaturalAire +Plus goes far beyond that, removing even those microscopic particles that stain walls and furnishings, or worse...enter our lungs. NaturalAire The Filters That Help The Environment. NaturalAire filters are the ones to choose if you're concerned about the environment. Harmful dyes and coatings have been eliminated from their manufacturing process, to reduce the amount of harmful materials released into the environment.