That is a very nice addition that your son made Mak Daddy.
Just like the warmer box there will be a range from approx 80 degrees to 225 degrees depending on the set temp of the grill and the ambient temperature outside.
I added a vent in the back/top that can be adjusted manually by sliding to let heat out as well.
Looked for a cover tht would fit the Smoker box while on the MAK so I wouldn't have to take it off. It is designed for a longer BBQ then the MAK and it allows it to cover the Smoker box with the excess. Not perfect , but will work for now