WHY?

The grip is already small.  How much smaller do you want it to be?  The Glock 26 is amazing, so is the 19, I can't imagine it being smaller than it already is.  Also, it would be less capacity.  

Any help on explaining why a single stack 9mm is wanted or explaining the dimensions of a 9mm single stack for practical use is a benifit compared to the current dimensions of a Glock 19 and Glock 26, both small with high capacity.  

Not sure why someone would want less capacity.....and not sure how Glocks can get any smaller than they already are.

Same reason that a G36 carries better than a G30

Because IWB sucks and OWB is not really an option in the summer

I want a gun around the size of a PM9, but with a Glock trigger, also single stack mags are so much easier for me to carry on my belt line than double stack.