What's this hole for? Applies to wood stove only! :-)

[Squeaky_6]

Hello All,
Bought a country comfort 300. I am in process of stripping it and painting it black. Haven't even fired it up yet.
Was curious if any of you knew what the hole in the back was for?
Also how does the baffle look?
Does this baffle require brick or a ceramic blanket on it?
The hole looks like it goes into the baffle, would this be for air for secondary combustion?
Thanks for any help.

 

[coaly]

Secondary burn chamber intake;
https://www.hearth.com/talk/ratings.php?do=viewrating&ratingid=2631

 

[Fsappo]

I don't know ceramic baffles were invented when that stove was made