ism sport saddle width of gap
 

Does anyone know how wide the gap is on the ISM sport saddle?
http://www.ismseat.com/sport_saddle.htm

It looks like it might get wider as it goes back, but I'm not sure.

I'm trying to figure out if I can squeeze something into the gap while I'm not riding, so I'd like to know how wide it is and how wide it could possibly spread if something were squeezed in the middle.