The lower portion of the panel where the connection needs to be made is very cramped while the upper portion is empty.   There is no room for an isolation valve. The handheld unit holder is poorly designed as the unit does not slide neatly into the holder.  Following the installation instructions, the flexible hose will actually be resting on the floor versus hanging nicely.  We have another shower panel that was cheaper but better design and it has better features as it shows the water temperature.  This one does not.  It functions fine, but could not rate it 5 because of the deficiencies mentioned above.