Although I cant give the full details here as this is the PG blog, I can say the Version 4 Revolutions are now available with a large list of improvements, repairs and new features.
If you own either the Naturals or the Silicones, simply wear the update that came with your breasts to get the Version 4's.
On the flip side, there are two entirely new models of Revolutions available.
The New Petites and the Mid range Salines.
Full details can by found by clicking here