I tugged on it pretty good. No give. I think it will work without the set screw. Amazing enough, the adapter fits pretty tight with the flange and ridge removed. I would have had to gouge a lot of material out of those nice adapters to make it work that way. This particular 2nd stage is dedicated to the mask, so I wasn't too worried about the mod. I believe a mouthpiece will still work on it with a proper zip tie if so needed some day. Otherwise, it will be sold with the mask.

I'm currently evaluating where I'm going to go with OC regulators for the future. I need more, but Apeks has moved on again. I liked them better when they were keeping the product line simple and not so flashy.

Once I decide, I may get a hold of you for a custom run.

Thanks for your help,

Eric