I had a stout tip on an Intertap faucet that was leaking (spraying) near the threads for the tip. Mine did not have an o-ring on the tip or the original. I found a #41 oring from Home Depot did the trick perfectly. I think I paid $1.49 for a package of 10, so I'll put them on all the tips. Just wanted to share my fix in case anyone else had the same issue.