I stopped in ACE Hardware on a Saturday whilst killing time waiting for MOCA to open. I have been carrying around a travel mug lid in my purse missing an O-ring for weeks. I lost the original months ago & never bothered to see about replacing it.
There was a older gentleman who quickly took me and my lid to the O-ring section of the store. We deduced the two options that might work and settled on a 79 cent option. It worked, it fit, I paid, and left.
I love that there are still old-fashioned Hardware stores where they actually have people who know what you need and have it in stock.