4" Starter Box is for through the ceiling installations.  Install it and paint it. Cut it to fit. Built in HT Pipe adapter inside.  Correct clearance to combustibles by having an air gap around the 4" HT Insulated pipe. Secondly, it is needed, or one of the other options will have to be used.  Furthermore, building your system requires some thought.  Have questions, we have answers. But, you have to be the one who decides what look you like. Do you want it round? But, I only want to create an air gap, I don't care what it looks like?  Do I even need one.  Possibly not, it depends on your type of install.

Can be used in place of Black Ceiling Support

Used in commercial applications

Galvanized

Dimensions:

A - 12"

B - 10"

The 4" Starter Box is a great choice when you go out through a ceiling. Do you have tongue and groove ceiling boards? A Starter box is exactly what it says. But it can be something different like this. https://flameinnovation.com/product/4-black-ceiling-support/ Furthermore, a lot of the time it is used in flat roof installations. Above all, Using a starter box gives you the freedom of how you want your install to look. Let us know.  In conclusion, we are here to help you figure out the best install as a package, then you will have what you need from start to finish with less trips to the hardware store. In short, less shipping of additional products to complete your install.