www.symphonyshades.com has a R 4.6 model I have a R5 model made on file
somewhere.. These higher R models seal on the sides in a track. From
what I have seen R 3.2 is common for cellular unless I am reading it
wrong. From what I believe I see you can easily take an R 3.2 dual pane
LowE argon window and go to R6.4 with Bali from HD or up to R 10 wth
Tri pane Low E argon and the R 5 shade. R 7.8 would be achieved easily
with dual pane LowE argon and the R 4.6 shade. Many houses actualy have
R 8 to R12 walls so the energy savings is worth the price of the units.