TetraWhisper Filter Cartridges 4 Count, Extra Small, For aquarium Filtration (AQ-78052),white

Does this work in the Aqua Culture 1-gallon corner tank?

does this work with a koller AquaView 2-gallon ?

Do you have the air pump for the XS

Is this one package of four for $13.?? Or is this four packages of four filters each? I would hope for the price it is 4 separate packages of 4 each.