I need help picking out fan flanges please...

So heres the set up I want:

Dayton 140 cfm Exhaust Fan w/cord

EA $90.95 $90.95 Dual Outlet Analog Timer

EA $14.90 $14.90 Can-Filter 2600 - 18" Carbon Filter

EA $49.10 $49.10 Can Fan Flange for 2600/9000 - 4"

EA $7.95 $7.95

Forget the timer. What I dont understand is do the fans and filter come with mounts?

How many flanges are needed to make a connection from the fan to a short piece of duct to the filter?

One more thing, can I mount a fan to a filter withouht any ducting?