Those vessels are made by 'Spectrum'.
The Spectrum Vessel and the Unger Vessel both work in the same-way, in that the....
water enters the vessel, flows down the tube, then 'UP through' the resin and out
The 'standard' vessels work by.....
water entering the vessel, flows 'DOWN through' the resin and up through the tube and out.
They claim that 'STANDARD Vessels' are inefficient because of the water flowing through the resin from 'top-to-bottom' causes channels to form in the resin creating dead zones where all rein is not being used.
I just give my 'standard' resin vessels a good shake after use, to mix-up the resin and break-down these channels.