A French door has a glass panes extending for most of its length. 10 / 5 means that it has 10 glass panels in 2 columns of 5 panels each column. Our French doors are milled from solid, whole-cut premium woods, and are the most authentic and elegant hand crafted doors available on the market. It is not merely for beauty and the style that the architects prefer wood doors. Whether it is heat or electricity, wood is one of the best insulators on earth. Since our doors are fabricate from whole cut solid wood, this ensures that there are no cracks, low quality joins, thin filler wood, or other inferior milling techniques that can cause wooden doors to seep warm air in the winter or cool air in the summer.