https://www.ebay.com/sch/i.html?_nkw=Allegro+Replacement+Filter+Kit+Pack+Of+4&_sacat=0&_dmd=2

Allegro Replacement Filter Kit, Pack Of 4

Regular price
$172.00
Sale price
$114.00

Replacement Filter Kit, For Use With 60 cfm Carry-Air(TM) and Wall-Air(TM) Filtration Panels, Includes (2) 1st Stage, (1) 2nd Stage, and (1) 3rd Stage Filter, Package Quantity 4