Why does my chimney enjoy 2 opening on top? i'm assuming this is a second flue, but why is there a...

i'm assuming this is a second flue, but why is there a inevitability for a second one. also should i get a multi flue panama or 2 singles?
On buying bright merchandise , where on earth...
Answers:    There are two separate flues going up your chimney. One may be for a wood burning fireplace and the other for the oil or gas burner that provides your most important heat.

The multi-flue hat is easier to install and looks better up there.
How can you control or murder ground squirrels?
SOMETIMES IT JUST CODE.
other times, it to prevent , one from gettiing blocked u p