Originally Posted by raybbaby
The X40 gives me more “room to grow”.
I concur. My length was around 6.875” when I decide to invest in one of these pumps, and since the size guidelines recommended the X40 for lengths of 7”+, that’s the one I bought. However, at this point I really think that it’s girth that would have been the limiting factor with the smaller models. Girth-wise, I fill up the X40 quite a bit during a pumping session, occasionally to point of discomfort, since the underside of my penis will expand against the edge of the sleeve.
That may sound like ridiculously huge girth, considering just how big the X40 is, but keep in mind a couple of things: First, as as_si_pe mentioned in another thread, there’s the issue of erection angle. In addition to being a pretty upright man, I also have a classic banana curve. So it’s good for me to have the extra space that the X40 provides.
Second, bear in mind that the important factor for the bore of the cylinder isn’t penis girth pre- or post-pumping; what matters is penis girth during pumping under high vacuum. I may have a fairly malleable tunica (I seem gain girth relatively easily), and when I’m under full vacuum, my girth expands massively. There’s obviously no way to measure it when my penis is in the pump, but there’s clearly very little room inside the thing, even accounting for skewed optics.