O-Ring Kits and Hardware Stores

[FallNAngel]

You could use AC o-rings from a parts store.. but your not going to save any money, there probably more expensive.. they are, I just looked

Well, there's very few o-rings you'll ever need to replace on an Autococker anyway

[Chojin Man]

do you measure o-rings from the inside diameter or the outside diameter?

[InexactMelissa]

Try here: http://www.marcorubber.com/ . You can get just about any size or material you want. I'm not sure if it came from this place, but in my house we have this big box of various sizes and materials similar to the kits they show on this site that usually contains about anything we need.