FROM 3 TO 7

I
remembering learning
how to count;
it was a grand accomplishment.
I
counted any and everything
from A to Z.
That was back then,
this is now.
IN
a recent porn movie
the plot was about a
studio looking for models
of both genders who could
handle the movement of
an erection from 3 inches
to 7 inches,
THE
movie presented those
auditioning for the movie
going from 1 to 3; 2 to 5.
IN
the middle of the auditions
the title was changed to
"__ to __"
can you guess what number?
":__" to  "__"!