2005 gmc 8.1L model Slt fuel filter

I just bought this sweet 2500hd crew cab 4x4!! well I want to do some general maintaince, it has 108k.I was looking for the normal canister fuel filter.And this truck does not have it on the frame rail.This truck is a black box style near the back end of the gas tank,This is my 1st 2500hd truck,and im clue less!! Can anybody explain this to me please!! I looked up a fuel filter on rock auto and they list a fuel filter for 400.00 !!Is this correct!! Please shed some light!!For 400.00 I better be able to clean and service this fuel filter like a reusable air filter I hope!! But im sure GM did a good screw job on this one!!Thx for any help

I beleive the filter is part of the tank unit, not a normal maintenance item, the 400 $ unit you saw sounds like the pump module.

no its not the fuel pump..i got 1 on order..from rock auto...im asking anybody what they know about it the fuel filter !! not what they mite think..like i said look up a fuel filter from rock auto...its 400.00

im all set I figured it out its a evap box