I'd like some help identifying the black parts circled in the photo.
It's a piece of 3mm rigid hose. It looks something like this:
That particular piece must have been cut from a larger piece, as the smallest it has ever come is 3L (3 studs) and never black at that size.
It's debated if cutting tube pieces is a purist thing to do or not.
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Cutting rigid hose is allowed in my opinion as The Sears Tower Architecture model (21003) had it as an actual step in the instructions. – Michael Verschaeve Sep 20 '18 at 5:42
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