Thanks for the info guys,seems like they last a very long time.
I also had about 60 grolsh bottles given to me and I find them really good to use and I will order some spare rings for sure.
I'm also not much of a grolsh fan unless its very very chilled then its ok I guess.
Probably for a...
Swing tops are definitely brilliant,I'm not sure how long the rubber ring lasts for as I've only just started using them for the last few brews. They are definitely easier than capping atleast more convenient.
You sure can reuse them if in need,but best to try and pry your bottle cap off with a cigarette lighter as they don't bend where as a bottle opener will put a kink in the bottle cap.
They are like new if pryed off with a lighter as it only touches the edge of the cap. I only know this as I reuse...