Made my drip tip and looking for o-rings. Where to purchase?

[bowyorang]

Hey! Had a few minutes in the shop to mess around and thought I would make a quick drip tip. It fits pretty snug, but I'm wanting to make a few different ones for me and the wife and thought it might be easier to get the fit right if I had some of the o-rings that are used on my drip tips. Anyone know where to purchase these?
Here is a pic of the one that I did. Nothing fancy. I think the next one will be longer. Something resembling a hookah hose tip...

 

[asdaq]

This thread came up a few days ago with a variety of helpful sources: http://www.e-cigarette-forum.com/forum/modding-forum/335735-metric-o-rings.html Size needed depends on your tolerances, but you surely know that.

Oh, I like the minimalism of the tip BTW.