Ah yes, but the right O-ring is always the answer. The last thing I want is a cheap O-ring ruining a good dive. Or better yet, failing at a critical time of the dive, on a critical piece of gear. That old rule of coming up as many times as one goes down comes into jeapordy. If one is willing to scrimp on something as small and cheap as an o-ring, how much more on something more expensive. God forbid, it is a life sustaining piece of gear.......Oh wait,!!! thats what scuba is all about!!