locking band chimney question

[Woodworm21]

I have a selkirk prefab 7" chimney (2inch insulated) that uses the locking bands. 2 questions:

A: on the top of each section you can see the insulation material, if I leave my cap off for any reason, will rain water and snow affect this material?

B: I have a new section of twist lock chimney, Can I connect this to the existing band lock to extend my stack over the peak? As in, is there a way to connect twist lock to band lock?

 

[goofa]

My Selkirk chimney I just installed was twist lock and also used the locking bands. So I'm not sure if you're referring to 2 different types or if yours is like mine and twist locks then secured with bands.