Quarter window 'sealing strap'?

[SM911]

I'm just about to put my rear window trims on, and I note that the 74-77 katalog has a 'sealing strap' between the trim and the body. Interestingly, the 69-73 katalog doesn't have the sealing strap identified, so can anyone tell me what it is? Porsche said it's available for $60 a roll, so I want to identify what it is, how it works, and if there is value in putting it on.
See item 30 in the diagram...

[Classic]

Scotts,

It's just the 3M dum dum tape, or terostat tape, like what is on your fenders when you place them on the car.

[SimonR]

I'm just about to put my rear window trims on, and I note that the 74-77 katalog has a 'sealing strap' between the trim and the body. Interestingly, the 69-73 katalog doesn't have the sealing strap identified, so can anyone tell me what it is? Porsche said it's available for $60 a roll, so I want to identify what it is, how it works, and if there is value in putting it on.
See item 30 in the diagram...

Scotty, I've got a roll, you're welcome to what you need. Mine doesn't have it, but it also doesn't have the washers/spacers so the aluminium strip is puckered in where the screws are. I don't have any leaking, but figured when I sort the windows out I may as well put it back in.

I'll grab it and take it into work in case you need it.

[SM911]

Tony - thanks. Only heard of DumDum tape for first time yesterday. Funny how these things happen.
Simon - many thanks mate - will take you up on that kind offer. Swap for a lunch of course