I got one of these for a Proton Metal second stage.
$11 LONG BITE BLACK SILICONE REGULATOR MOUTHPIECE - (eBay item 300114371823 end time Nov-19-07 15:24:18 PST)
I slide it all the way forward until it contacts the "air tube" portion of the second stage body. Then I use the tiewrap. It fits my mouth quite well, leaving the exhaust tee resting gently on my chin. Had it about a year and a half, and it is holding up well. Comfy.
The Mares mouthpiece would be OK if you had a mouth like a bluegill.
$11 LONG BITE BLACK SILICONE REGULATOR MOUTHPIECE - (eBay item 300114371823 end time Nov-19-07 15:24:18 PST)
I slide it all the way forward until it contacts the "air tube" portion of the second stage body. Then I use the tiewrap. It fits my mouth quite well, leaving the exhaust tee resting gently on my chin. Had it about a year and a half, and it is holding up well. Comfy.
The Mares mouthpiece would be OK if you had a mouth like a bluegill.