What are these clamps for?

I bought a Vans RV6A with a Lycoming O-320. It came with a new Vetterman crossover style exhaust and 2 different style heater baffles (1 single port and 1 dual port) and some support brackets but no directions. It came with 2 Standard P shape style and these 2. What I do not understand is these 2 have a small alignment stud welded to the inside. Thanks for any help understanding what these are for.

Vetterman install instructions and photos

Here are the Vetterman and Robins Wings (heat muff) install instructions I received and some photos to explain the pin clamps.
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Thank you Johnnright. This should help.

I had a set of those on my C-170. They were used to hold a set of extensions onto the exhaust pipes. The protrusion bit was used to make sure the extensions did not fall off the pipe incase the clamp became loose.