This item is a spare replacement air filter for BedJet 3 Mini. All BedJet units come factory installed with a lifetime washable air filter that never needs replacement. Simply remove every 3 months, rinse out the filter clean under running water, lay flat to dry, then place it back in the unit. Spare filters are needed only if you wish to have extras on hand, or if you damage your air filter during cleaning after your warranty has expired.