SparticleBrane:
I agree with Perrone, since the low pressure hoses that you use on your normal second stages are the same in terms of size and internal diameter---it's just that the low pressure inflator hose has a slightly different fitting.
Not magic, but the Atomic hose IS different.
If you compare the internal diameter of the opening the threaded
metal fitting that screws into the first stage it is noticeably larger.
Also, the rubber hose itself is slightly larger as well.
(The thread size is still the same, it is the air hole size inside the
fitting that is larger)
And for those doubting Thomas' out there I do have a picture
(which I couldn't get to attach) that I can send to you.
However, I did measure it with digital calipers.
The Atomic fitting has a 4.9mm opening and the other hose
had a 3.8mm opening.
Given that surface area is proportional to the square of the
radius of the circle, going from 3.8mm to 4.9mm diameter is
1.66 times or 66 % bigger surface area or hole size.
This should make a difference in how well air flows.
Whether the extra flow is really needed in real life, I guess could
be argued.
Math follows below:
3.8mm diameter = 1.9mm radius
4.9mm diameter = 2.45mm radius
(1.9) * (1.9) * pi = 11.34 square mm
(2.45) *(2.45) * pi = 18.86 square mm
18.86/11.34 = 1.66
NOTE: all "std" low pressure hoses may not be the same or have
the same sized fittings but this is the result of my comparisons of
actual hoses - not just supposition.
--- bill