Canopy question

If you look at the size of most of the canopies made in the United
States, they appear to be limited to a certain size. ( ie: RV-6,
Lancair 360, etc. ) their height seems to be limited to around 16-18
inches. If you look at most of the European canopies ( Ban-bi, Storm,
Sting, and the new one from Poland that was recently shown on this
news group ) they seem to have canopies that extend a lot lower.
Given, their top longerons are lower also and their canopies can
extend a lot lower. GREAT visibility. Are they just able to get
larger pieces of plastic across the pond or what?

Neal