All standard-size Austin Air units are compatible with any standard-size air filter, meaning you can easily switch between different models. For example, if you originally bought a standard-size HealthMate® Air Purifier but want the benefits of a Pet Machine®, you only need to buy the Pet Machine® replacement air filter to upgrade your air purifier's capabilities.

When ordering your replacement filter, it's important to carefully choose the correct size and type to match your unit. Be sure to verify these details before finalizing your order, as returning incorrectly ordered filters may result in a restocking fee. To confirm the size of your current filter, check for a label on the underside of your unit. If the label says "Model HM400," it indicates that your unit uses the standard-size filter.