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I've heard that Aqualung is still making the military version of the Conshelf with a metal second stage. The US military has rated this reg to 190 feet and 37 degrees farenheit. The conshelf has the same parts as a Titan and the design hasn't changed since the 60's (internally) There are more Conshelf parts around the world than any other brand and will continue to be for a very long time.
I'm thinking the next reg I get might be this just because it's extremely simple and bullet proof.
I have conshelfs for all of my single hose diving regulators. I have two 22s that I use for diving doubles with DIN adapters on them, a 14 that I use for recreational diving, and a VI, XI, and XII for vintage diving. I think the conshelf is the most reliable single hose regulator ever made. I have put mine through the ringer and they have never had any kind of failure. I used one that had the original HP seat in it from 1965 and it still worked. These regs are bomb-proof. The legend and titan use conshelf parts in them, so in a way they are the modern (non-military) iteration of the conshelf. If I was going to be a dive bum, and I could only carry one regulator, it would be a conshelf.