huge, heavy-duty, cap. I replaced a delrin cap with this one, the opening at the top is almost twice the size of the other one. Metal stayed cool even under heavy vamping sessions.

The metal doesn't get hot. Perfect airflow. Gonna order some more soon

I figure it works just as a chuff-style cap is meant to, but it's the first one I've had. If it's your first, too, expect air flow like you didn't realize was possible. I had always used the standard size, like the one that comes on most sub-ohm tanks. When I put this one on with my air slots at full-open on my Troll RDA, it felt and continues to ...Read MoreRead more about review stating Very Airy

feel very much like an almost unrestricted inward breath. It's ridiculous in a good way. Sometimes for a change of pace I'll put my standard tip on again, especially if I plan to be sort of chain vaping, but the chuff cap is standard equipment on my Troll probably 80% of the time, now.

With the airflow adjustment on the RDA itself, it's still totally doable if you want to tighten up the draw to an extent. For the extra couple bucks, just put this thing in your cart. If you hate it, chuck it in the odds and ends box and don't lose any sleep. Read LessRead less about review stating Very Airy

Thought it was 22mm, was like aww man and sold it to a buddy who has a 28mm and it just straight up didn't fit with multiple other O rings we tried. Sux