Quote Originally Posted by Bob Salomon - HP Marketing
" It allows the camera to fold easier but requires thinner bellows "

The reason for the double taper is so the standards can be collapsed so that they are almost touching when the camera is folded for travel. Only the 45 requires a double tapered bellows. The 23 model does not require one but the bellows extension is several inches less then with the 45.

I'm glad, I got rid of the double-tapered bellows. Nothing but trouble. I'm much happier with my new single-tapered version.