For those of you looking for glass tubes to fit the Pro V endcaps, the Siam Mods glass tubes will work but I have to qualify that statement. The fit of the caps is snug enough but the outside of the tube is not quite flush. Also, perhaps due to the height of the beveled top cap, the carto just barely reaches the o-ring in the top cap. I'm using the regular size siam glass with a standard length boge carto so can't speak to the XL size. But it does work... no leaks and I can grab the pv by the tank and lift with no slippage.
Also the green glass tank I received has decorative ridges 1/3 from top and bottom which may exaggerate the flare of the glass at top and bottom. Possibly, with the clear or blue tanks, the flare past the outside edge may not be as pronounced due to the fact that they are straight tubes.
Regardless, if you're not a nitpicker, imho it looks and works fine although for the price of a Pro V and the Siam glass you could just as easily buy a Prive tank but they aren't glass either.