These pumps will fit most drums with a 51mm neck size.
They fit the large bottle of the Vista 7.5kg packs and also the Resin pro transparent and epoxy table5 large packs.
Each pump comes with tube that will need to be cut to length. This can be sized up by measuring on outside of bottle before placing in tub.
Because the pump pulls from bottom of bottle it ensures no air in the pump, until you reach low level. Each pump is around 30ml of fluid.