Mine had a coarse foam filter(some later ones had an Expensive_extra cartridge)
Old filter failed--so wrapped a strip of foam,2 layers,and an old Nylon Childs T shirt stiched up+Big home made rubber bands.
Can get spray moments if too full/Soapy
T_shirt made better for saw dust, wet filter for a bit of fine dust!
(But i'm not a Pro so have time to faff about with after cleaning in a tub)
" Excuse == I'm a skinflint"