The 425 is the flagship model having been designed for the most common new construction dryer exhaust configuration. While there are a few exceptions, it is primarily used for venting upward in 2 X 6 walls. Where wall depth is restricted, it can be installed in a 2 X 4 wall with a 1" furring strip. The only time the 425 should be inverted is to support pedestal or stacked units for downward venting. This model was designed to allow room for other mechanical components in the cell of the wall. It is narrow enough to share plumbing or electrical runs.
To provide dryer-type flexibility (in the event that someone wishes to change from a pedestal dryer, for instance, to a floor standing dryer), select the new Model 480 for a standard installation.