I purchased this sealing "thingy" at Home Hardware. I am not sure where you could get it outside of Canada, but if you googled the brand name, I am sure it would show up somewhere.
|Several bags and the pump come in this box.|
|The pump and one of the small bags.|
Extra bags in various sizes are available too.
Anyway, if it doesn't work for silver, you can always store freezable foods in it - lol!