510 "XL" Cart vs the 510 "Mega" Cart

[Mvgratz]

I thought they were the same thing. But after looking for a XL Cart I see they are listed for sell seperatley on vendors sites. That leaves me with a few questions...
Do the reg 510 carts hold ~1ml, XL 510 carts hold ~2ml, and the 510 Mega carts hold ~3ml??? And... can you use a XL atty with a mega cart or vise versa???

 

[Stosh]

The regular 510, XL 510 and (ego) mega 510 attys are all different, use different carts for each.
An XL is a longer version of a standard 510, so there's more room for filler, more juice.
The mega attys are fatter around, have a larger bridge and coil, and bigger cart for even more juice.

I would recommend the blue foam mod for mega attys, wicks much better and leaks less.