there is, sigh, so little standardization in dust removal piping.
if I'm not mistaken, and that's the same one I have previously used,,,
the outer diameter big end of that adapter is 4" - and the outlet on the band saw is 4" - so they will only connect via a sleeve.
but the band saw outlet is cast iron and has a slight taper.
so the sleeve slides on so far there's no engagement left for the adapter.
so a longer section of 4" could be used as a 'super sleeve'
eventually you have to expand the shop to accommodate all the sleeves elbows sleeves on elbows etc etc etc
there's a fortune waiting to be made for the person who supplies dust ducting with male & female end fittings....
as witnessed by all the clever homespun systems, gates, attachment points, etc people have posted here.