What the heck is this thing

[ranger91]

ok i have a 98 explorer 5.0 that i have swaped the engine into a 91 ranger. now i have an extra fuel line? i have no idea where it goes other than to a canister at the back end of the explorer what is this and do i need it?
any info would be great.

 

[IZwack]

Evap: http://www.autozone.com/az/cds/en_us/0900823d/80/0b/98/5a/0900823d800b985a/repairInfoPages.htm