AirBedz Pro3 Inflatable Wheel Well Inserts, One size fits all Pro3 Series mattresses (PPI-301, PPI-302, and PPI-303). AirBedz Wheel Well Inserts convert your AirBedz mattress into a regular air mattress for use in tents or as a guest bed in the home. (Mattress sold separate) Simply inflate and place into the wheel well openings using the attached Velcro tabs.