I'm waiting for my cjb to get back. A stock 801 tip will fit in the top of it, so I'm presuming that it is a 801 size or larger. It is made of brass. Mine had a single small air inlet hole at the bend of it.
I seem to remember him either posting or stating in a video that he was able to reengineer a stock atty and take out what he considered to be fail points in the design; i.e., components in stock attys that he deemed set up to eventually fail.
This ain't no stock atty, fellas. A single drop or two of juice could almost fill a room with thick, tasty vape. It's his atty that's the reason to buy a cjb, not the juicing action, IMO. I suspect, this-and lack of time-is the reason for him to not build his atty for other mods. A carlos atty on an 801 thread with a great 2nd gen pv would create the ultimate 3.7v dripping machine, case closed.