Greg Reid.
But if the seal does not seal it will loose vacuum & not work properly.
I (experimenting ) used clear silicone at the top of the decent one left then sucked it down with the mighty vac , it seemed to work fine that way & held the headlamp door up for over a hour until I released it.
MAYBE a "O" ring on the top of the inner will keep it sealed up?
I think I will order 2 sets in case I screw it up LOL!
I also plan to use some kind of rubber protectant on it to prolong the rubbers life.
I will Give Mike Phillips from Auto Geek a call & see if the Detailing Gods have come up with a Rubber coating yet maybe something comparable to Ceramic Nano Coating.
Mike has always got a gaggle of new products up his sleeve.

SR66
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SLOWRIDE "take it easy"
https://www.robharleydetailer.com/
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I'm not prejudice, I hate everyone Equally.
The best proof that there is intelligent life in outer space is;that they haven't made contact