I had a look at the breech seal on my Lightning SE springer the other day and noticed a slight amount of what looks like chaffing so I simply popped it out and reversed it. All seems to be fine and dandy but I intend to replace it but on looking round there are two variations available, one is black like the original and the other is clear, with a purpose made slot supposedly to stop the seal "popping out", and also supposedly better?

What does this slot actually do and can I use this one in lieu of the black one?

Thanks.